Craig's Stereography
-my combined stereoscopic pages
Last worked on: June 30th, 2017
(Composed in Netscape-4.7, 800x600 prime. Best if re-sized for a squarish window: 
We no longer do stereography commercially
and what follows is often quite out of date.

Find>>  How to turn Fuji-W3 camera images into stereo prints: step-by-step - The W3 camera
- Our old 5 inch card viewers & Sets of Viewcards - Working with available cameras, Fuji's W3 and digital processors -
T-Plate Mounting Steps - Open Mounting Steps - Glossary - Addresses - Accessory Lenses for Nimslo - Bifold format -
Print Stereo Film - StereoSynthesis - Chicago - 6x13 - The RWVer and Standard Holmes/Bates format Stereoscopes -
My past Stereo Services - Freeviewing - Tutorials: trimming & mounting - sample view - Join NSA & SSA -

Stereoscopy is older than photography --by about 6 months, so inventor Sir Charles Wheatstone had to draw the first viewcards by hand(!) in 1838. It was Wheatstone coined the term "stereoscope" at his presentation to the Royal Society (of London --the oldest national scientific society in the world), and (amazingly) he was the first person to put two and two together in order to create a stereoscopic print pair. The Renaissance artists, such as Leonardo da Vinci, were aware that binocular vision allows of depth perception, and there's indications for such awareness among Greek philosophers. (Corrections here thanks to reading Carol Jacobi and Dr. Brian May.)

 ~ Wheatstone's stereoscope was a bulky affair with mirrors that sat on a table.

Next came Sir David Brewster's much smaller box stereoscope, suitable for passing around in a social circle.
Finally, in 1861, came the lightweight, open, skeletal stereoscope --a rude version of the ones we're now using.
This was designed by Dr. Oliver Wendell Holmes (Senior --father of Supreme Court Justice Holmes) and jointly developed with his craftsman friend: Joseph L. Bates. Holmes, who did much to popularize stereography, chose not to encumber his invention with patents (bless him).

 ~ Until about 1930, commercial photographers were usually also stereographers and millions of affordable Holmes-Bates 'scopes were manufactured. With the advent of inexpensive half-tone mechanical image printing, what was originally a limited, upper middle class "parlor stereoscope" experience, became a working class delight as well. Viewcards ended up being given away as grocery store premiums.

Some attractions of print pair views are simply due to their being stereoscopic: a fascinating play of perspective, an ethereal feeling of having "presence" in another time and place.  There are subtleties as well: a graceful balance between a moment of life on the front of the card and its interpretive legend on the verso, a felt connection with the subject and the stereographer.  The view card in your hand is a mixed medium with power, reach, and an inherent poetry.  Stereography is an art form to contend with, worthy of both lighthearted and serious practice.

With these strengths, viewcards do well as a humble witness to life.  Simply match images of appealing subjects with well edited thoughts.  The medium itself carries my ordinary efforts with its engaging illusion and recognition of life.  Each card completion becomes a self-documented cultural artifact, registration for a visual delight or bit of history, and another portal to the vastness of Nature and human endeavors.

As life rushes by, new images and mental abstractions of old ones quickly displace the few visual experiences we even try to focus on --like the press of so many curiosity seekers gathering to the scene of a happening.  But in the view card's stillness, we can find the personal time to clearly see and "take in" --perhaps a detail made visible only through stereography, the seeming reality of a scene otherwise lost to living eyes, --a face: still fresh and earnest in the warm light of a distant summer.

Thanks to Carl D, here's a link to modern times stereographica:

Popular and serious stereography got a tremendous boost with the introduction of Fujifilm's delightful model W1 and W3 cameras. This modern, durable, well thought out and affordable instrument, set on automatic, will reliably nail the exposure and color of nearly anything it's aimed at. Unfortunately, inventories of its production run have sold out and there (so far) doesn't appear to be a successor on the way. What new and old options we still have for taking stereographic photos follows. Here and here is what I've already posted about the W3. (Note that the W3 has user feature improvements but is otherwise very similar to the W1.)

What I see at (in no special order, but leaving out video only, mobile phone accessories, and "Holga" class cameras):

* New and used W3 and W1 cameras at about twice the old prices.

* A new (to me, anyway) 3D camera/camcorder entry from Sony, but I'm not sure it's being officially sold in the USA. From reading a poorly translated article, I see its emphasis is on automated flexibility between 2D and 3D modes, has a respectable pair of sensors (5 megapixel) and is capable of HD video. I've seen a new asking price of $395. This is the "Sony MobileHD Camera Bloggie 3D MHS-FS3".

* Something dubbed the model "DXG-018Y", which is clearly a digital "box camera" with fixed focus lenses. My Amazon page save came out badly, but I can make out that it has an LCD screen, color balance options, extremely short focal length lenses ("2mm") and tiny sensors ("1/9 inch"), which capture "0.3" megapixel images --which must be close to a standard definition video frame --which isn't enough resolution to print a standard sized stereoscopic pair (3x3 inches each frame). Other than that, the lone customer/reviewer is happy with his purchase (at $87.99). It's supposed to have been sold through since 2011, but it's new to me.

* The uninspiringly named "Takara Tomy 3d Shot Cam", described at Amazon with lame English. It's only $47.47 and it ships for free --straight from Japan. (In 2014, this same camera shipped free for $26!) For $47.47 you don't get an LCD display and the image pair have amazingly low resolution (about 150x200pixels, according to one reviewer). The lenses are (of course) fixed focus --no doubt with amazing depth of field.

* Panasonic's "Lumix 3D1-K". This is a real, 12 megapixel camera, being sold used at Amazon for $548.55, but I see a (once upon a time: 2014) new price of $180, straight from Japan --so shop around. Looking at it, this camera should be great for close-ups, interior and lawn party shots, but might leave a bit to be desired when shooting scenics, since the lenses look rather closely spaced (30mm apart). I read that everything about it is in Japanese, but there's a downloadable manual in English.

~ The JVC "Everio Gs-td1" camera/camcorder --at about $500 (and that's all I know at this point).

* The "Aiptek 3D-HD" camcorder/camera --has been around since 2010, when it sold for $200, and can now be had for $129 --shipped for free. With its 5 megapixel sensors, I can rate this "almost a real camera". The image pairs I've worked with were quite decent. See my early extensive reviews hear and here (and scroll up).

* Then there's Vivitar's "Vivicam 3D" entry: a 3D digital camera for $29.99 at Amazon --shipped free, but you'd best read the reviews. Be my guess: this was an abortive production run from some years ago, now being dumped, and the internal lithium battery has pretty much expired. (Read the buyer reviews.)

I've been wanting to make a statement about American stereoscopic movies and how they drove a short lived revival of amateur stereoscopy, but I lack depth in cinema --technically and culturally. Here instead (and I hope it stays posted) is a thoughtful blog by veteran cinematographer John Bailey, ASC., --who extends a deep bow to the research and publications authored by the NSA's own Ray Zone (who died in 2012).
My impression: Mr. Bailey is wary and a bit put-upon (justifiably) that the hustle of profits and fashion driven innovation --demands that he now confront (and probably integrate) stereoscopy into his repertoire of expertise. (As a life-long technician, I'm deeply sympathetic.) This technically and professionally competent man is just enough of a "3D" outsider to have a valuable point of view --about his neck of the stereoscopic woods.
"Working in stereo movies in a responsible way is not simply a point and shoot affair, even under the simplest of conditions. --- There is a dictate that became a mantra doled out by the workshop instructors and taken to heart by we eager students: 3-D in movies is NOT REAL. Like an Escher drawing, it is an illusion. Our actual eyes simply don't function the way 3-D movie imagery does. In constructing the 3-D movie frame we professional cinematographers have to evaluate carefully all the visual elements contained within the shot, as well as their cumulative effect as the sequence develops, shot by shot."
* Throughout this opinion piece, Mr. Bailey (and, presumably, the instructor of a workshop in filming stereo movies that he recently attended) accepts it that the camera/s lenses will have both interaxial (camera base) and convergence adjustment --or: "toe-in". While this is a convenient way to deal with the stereo window, I hope that better awareness and equipment (or creative control during the editing stage) will one day make this a practice of the past.  In the indeterminate meanwhile, we'll have to rely on the cinematographer's good sense that "something is wrong" --and he/she then backs off on the interaxial.
I also commend the comments section to your attention, such as: "Among Avatar’s innumerable failures, its stubborn refusal to develop any kind of grammar (or even acknowledging that a new one was required) was the one that angered me the most" (by Benoît Perrier). Ray Zone also adds some thoughts about the inevitability of 3D cinema.
I've now reconsidered my first impressions of Avatar --that it was the most competently executed Hollywood stereoscopic motion picture I've seen, plus culturally/thematically friendly to me in that it identified with the (idealized) victims of our sick, imperial, corporate run nation. So I still give it "two thumbs up", --but yes: even the time I first saw this movie, I would have preferred it (personally) if the stereoscopy (interaxial/"deviation" content) had backed off a bit. (Gosh: I felt like such an old man --gripping the arm rests of my seat, but I realized that a younger audience was enjoying the ride.)
Avatar, good as it was, could have been more subtly and aesthetically executed --but probably to the detriment of the boost it gave our stereoscopic industries in general. Hopefully, venture capital and patronage will support an ever maturing "grammar" of stereoscopic cinematography.


(use red-blue 3D glasses for the kitty)

* On 8/6/2006 I discovered a coinage and trademark use of "StereoSynthesis" that was previous to my own use in 1993. David M. Geshwind patented a process he called "Stereosynthesis" for converting 2D cine footage into 3D in 1990. I suspect that it wasn't the high resolution "in the round" photo-realistic rendering I was doing in 1993, but it was very advanced, fast, and digitally automated. By contrast, I painstakingly plot out my sometimes pixel level manipulations by hand and then execute my plan with a general purpose graphics program. I never applied for any patents or trademark protection, but I did quite a bit of work through my agent, James Curtin, during the 1990s.
It's fun to take a regular (non-stereoscopic) photo and render it into a 3D image. Eventually, our "Tutorials" section will supply the information you'll need to do this StereoSynthesis on your own --skills that a number of stereoscopists have now mastered.

For commercial services in rendering 2D to 3D (especially as lenticular displays), contact Peter Sinclair at:


"High resolution" in the early 90s was different from what's considered even adequate resolution today.  Back when 150 line screen on a 2540 dpi commercial press was considered real quality, we used a shop with a row of million dollar Heidleburg presses in Ohio to do our process color printing.  (The finished images were to be viewed with 4 to 7 inch focal length lenses.)  When I proofed the work, using a troublesome dye sublimation printer, I thought I could see a gain when our images were supported at 300 dpi, so I sent in the image files that way (by FedEx on expensive, delicate "SyQuest" cartridges).  They initially complained at the other end about "needlessly large" image files, which ranged up to 7 MB each (equivalent to 2.5 megapixels) for our small format print pairs.
The largest image I could open without crashing my computer was about 20 MB --which was also the largest uncompressed image from a Kodak Photo-CD scan file.  Today, of course, 8 megapixel ( 24 MB file size, uncompressed) consumer cameras are commonplace and the local shop will ask you for that much image to make a best quality 16" wide poster.

Anaglyphy (to be viewed with red-blue or red-cyan glasses) works quite well with computer monitors. Here's an anaglyphic stereograph that you might enjoy.

Chicago - 1968
(use red-blue 3D glasses / click for 100Kb version)

*Our old products, the Model #5h viewer (for 5 inch cards, Brewster type for 5 inch cards) and sets of viewcards to fit them are no longer available.. We've given many views and viewers away --which seems a lot simpler, and just as "profitable" :-)))
Monolithic Processing Might come back, but it will have to be offered by others --sorry.
I have two major reasons:

* I'd like to focus on pursuing our own stereography.

* I found it too difficult to contend with scratches and dirt on film emulsions. Possibly, film scanners with "ICE" scratch removal technology works for stereo pairs --and someone with such a device will step up to bat and make print pairs (like this one) --from our stereo formatted 35mm film.
                                               (view by Nancy Lee)
Dear Stereographer: It's fairly simple to make your own views --now that we have such excellent color printers, both as desk tops and as digital commercial rigs in photo departments. My suggestions:

1) Write to me (with your SASE) for a free tutorial CD on how to create your own print pair view cards, and consider joining the Stereoscopic Society of America.

2) Have your digital finished work printed with a department store Fuji or Kodak machine. Their outputs are as good as I ever achieved in the color darkrooms I've built.

Office and home desktop printers tend to show some "image structure" in the highlights --but are "good enough" for most of our printing needs, and certainly for "free-view" pairs. However, many photo quality desk top printers have become affordably available (but watch the per print operating costs).  We now use a Brother brand "all in one" MFC-J985DW inkjet which promises penny/page black and white, nickel a page color --and the image quality is great (using premium papers). (This is break from my 27 year string of excellent HP printers, due to high ink cartridge costs --and a lot of sassy screen messages when I refilled cartridges.)

European "6x13 format" and American "free-view" pairs on (about) 5 inch wide cards are something like 71% the image size of traditional 7 inch wide Holmes/Bates view cards. If you're going to use a 4x6 output device (which is now about the only size available) you might wish to print the entire ("monolithic") card that way, and have plenty of room to spare.


*** Click for our template patterns and trim/mount steps. You'll need them for trimming/gluing print pairs to open cards (and/or write for the latest tutorial on CD with your SASE.)

* If you're still using film, please keep your film strips in clean sleeves.

The average shooter will be better off when photography is all digital (check out the Fuji W-1 3D camera): no dirt or scratches to permanently ruin your images. Peg and I still mainly shoot digital now.


Digital Comments: I suggest that you consider archiving non-Kodachrome (E-14) color film to digital files on DVDs (more archival than compact disks ("CDs"), provided you can find and afford a quality scanning service (perhaps at Evergreen Film Service in Eugene). E-6 transparency and standard color negative films (including Illford's XP2) have better life expectancies than in the past, but 20 years is still likely to show some deterioration.

Many are unaware that most magnetic media, digital and analog, is similarly rated (though I think it's more durable than commonly thought). The "good news" previously posted here --about CDs (like Kodachrome) being rated to last 90 years --has become "inoperative". Now folks talk about 15 to 30 years for good brands.   :-(((   However: if you stay on your toes, you'll be able to "migrate" your image files to whatever comes next. --Same goes for your digital camera images: archive your files to DVDs (for now). (I don't know the archiviality of Blu-Ray, but that technology may have arrived a bit too late on the scene.)



* The only sane way is to simply take a digital photograph of a bright and evenly (back light box/table) illuminated page of negative film strips.

* Simpler still is to order (and hang onto) an index card when you have film developed and scanned to disk, or maybe print out your graphics program's "thumbs" browsing display.

Happy Shooting!


Accessories for Nimslo cameras.
At this point my inventories of prepared lenses are depleted. For more information and for advice on making your own accessories *-click!-*


You might find the folding "6x13" format viewers we and The Added Dimension use to sell at American Paper Optics or at:

I no longer offer the "CedarEdge" wooden stereoscope), nor the affordable stereoscopes/viewers for 5 inch wide card print pairs.


"6x13" loosely refers to a pair of images that are each about 2-1/4" wide on a card that's about 5" wide and often about 2.5" high. Alluded to is the 6x13 centimeters of old European medium plate cameras and more recent paired "medium format" frames from 6x6 and 6x7 format cameras --which frames are actually about 2-1/8" square. This range of format is also called "free view" because it's easy to "spread" one's eyes and fuse the pairs without benefit of an optical viewing device.

Obviously, affordable printing methods are challenged to turn out the high resolution needed for stereoscopes, and this smaller format is a bit more demanding. However, the results can be very pleasing, as were the dozens of commercially printed projects I've been involved with. Most of all, the gain in affordability, simplicity, and mailability simply requires that we make this format work. See our 6x13 page for more information.

YES: I still make (and love) old style 7" wide card-like views.


If exchanging stereoscopic imaging samples and ideas sounds interesting to you (either digitally or with traditional photographic pairs), check into the NSA ( and SSA ( Costs can be kept low in the photographic circuits by (say) simply "shifting" a conventional camera to make stereo pairs (an SASE brings you instructions). (There are modest NSA/SSA dues.)

And don't miss the International Stereoscopic Union's web site at:
*Discover MORE products, services, books, and other stereographica!
3D TV! (
Visit the "3D Web" (Bob Mannle's site + others)

Visit the Quellen Company {you can get Q-VUs through},

--which makes and supplies "Q-VU" mounts. They do for print pairs what 35mm slide mounts do for transparencies. You order suitable print pairs from a stereo format friendly processor, template trim them (ask me for free instructions) and drop them in. Quellen also has mounts and affordable plastic viewers for medium format ("6x13") pairs. (Quentin's site provides some interesting medium format links.)

General Addresses

ADDRESSES FOR STEREOGRAPHERS (out of date --sorry. Enclose a stamped self-addressed business size envelope when requesting information.)

* American Paper Optics, for all items formerly sold by The The Added Dimension and many services in coöperation with "StereoType". Also see

* Berezin Stereo Photography Products / 21686 Abedul, Mission Viejo, CA 92691. Berezin is our #1 supplier --of most everything. Visit his web site at* to see his new products --including actual digital still and video 3D cameras! (Check the reviews, however. These cameras have limitations.) (949-215-1554, fax: 581-3982)

* 3D from Dalia / PO Box 492 / Corte Madera, CA -94976. Dalia Miller's catalogue is actually a proprietary magazine that you subscribe to --filled with a wide range of quality antique and rehabilitated equipment and media. (415-924-3356; fax: 6162)

* Studio 3-D (Ron Labbe) / 30 Glendale Street / Maynard, MA 01754. Format conversions, mounting, processing, and projection services. -

*Taylor Merchant Corporation / 5 Grayley Place / Huntington Stn. NY 11746212. Nice folding viewers for 5 inch card format views, lenses for that and standard format stereoscopes. See:

* Cygnus Graphics / PO Box 32461 / Phoenix, AZ 85064-2461. My what great stuff!

For the exquisite wooden "SaturnScope" contact:

*Corner Rounder: Lassco Products, Inc. / 485 Hague Street / Rochester, New York 14606 (716-235-1991).

Regular Stereo Processing:

To the best of my knowledge, we only have one choice for getting prints from negative film frames, but it's a good choice.  I'm currently having a discussion with Panda Labs, which has been doing custom stereo printing for many years, to see if they want to offer "standard deals" for our 35mm 5p and 4p formats. Please stand by for more information: specifics and prices.

* Panda Labs
533 Warren Av. N
Seattle 98103                        phone: 206-285-7091

This is a widely respected lab which likes challenges and will print to/from custom formats and special emulsions.

** If this is all too much trouble and expense, consider buying the new Fuji "W-1" or the Aiptek stereo camera systems, going the synched cameras route (film or digital), or the Loreo 1-2-3 from Berezin  --for which I've made some comments and suggestions per: digiprint/

* Four Star Photo of Georgia
Main Post Mini Mall Exchange
Fort Benning, GA 31905  As of 8-12-2010, their web site is down, the main phone number is disconnected, the other one just rings, and the e-mail address I have for owner Richard Maeher bounced.

* The Camera Shop of Klamath Falls bought into a new photo processing system 5 years ago, but found it too inflexible to allow of handling our 5p and 4p stereo formats.

* Grand Photo of St. Paul Minnesota has a Better Business Bureau listing indicating that it's no longer owned by Mark and Janet McCoy --even though the Grand Photo on-line presence still suggests that, given encouragement, they might be willing to once again try their hand at printing stereo pairs.

*, has some very interesting services to offer, but the web site doesn't appear to have been updated since Windows-95 days, their 877 number answers to another business name, and I got an anonymous "leave message" using their regular number. I'm waiting for any return on my e-mail ping.

This fellow offered the same kind of digital service I tried to offer --plus he added interesting twists in being able to return a variety of digital formats.

Other Services and Suppliers:

Lenticular: * Many who call and write are seeking lenticular processing for one of the many 2, 3, 4, and 5 lensed cameras that have been sold. Contact:

* (I worked with the owner-operator Peter Sinclair, nice guy  :-)

* Folder Mounts:Q-VU: is a print pair mount which does for prints what slide mounts do for transparencies. They're available in a variety of colors and styles. Q-VU / 817 E. 8th Street / Holtville, CA 92250 at:, and from suppliers like Berezin.


* Doing business as the "Red Wing View Company", I designed and made the original "split tongue" Red Wing Viewers. Later on I supplied just the brass parts for Luther Askeland's beautiful version. These two are all that remain and aren't for sale.

"His principal income, it turned out, was from a line of lovingly constructed replicas of the 19th-century stereoscopes that provided entertainment in Victorian parlors along with the spread of photography during the 1850s and 1860s. Invented in 1849, the stereoscope is a simple mechanical device that allows two pictures taken from a slightly different angle to be seen separately by each eye. Thus it produces the illusion of three-dimensional depth, demonstrating how perception is shaped by the angle of vision and the habits of the neural system. Luther sold them to collectors throughout the country."  --Rhoda R. Gilman: "Luther Askeland and the Wordless Way"

* A Photographer's Place (use to be at: PO Box 274 / Prince Street Station / New York, NY 10012-0005), sadly, went out of business in 2001 --after a long run as a treasured resource. See Bill Pierce's goodbye. Among  Harvey Zucker's expansive offerings of books was a huge stock of reproduction ("litho") viewcards (I bought a chunk of it) and the stereoscope I once resold as "The CedarEdge":

* These 'scopes are still made by Don Claymore ("The Claymore Company", wholesale only) out of finely finished and varnished hard and semi-hardwoods like walnut and mahogany, which he saws and mills. He sells all that he and his family can turn out, turning down huge orders (Toyo wanted 10,000) so that he can remain hands-on. We're no longer offering these Standard Holmes-Bates format stereoscopes, but they're widely available in gift shops and museums --for $100 to $150 retail, which includes a dozen litho reproduction antique views. Here's a recent story about Don, wife Shirley and family in the Delta County Independent:

This stereoscope is available from Berezin Stereo Photography Products (see:

At one point I had some input as to its geometry and optics. The design turned out well. The CedarEdge comes with a good leather hood, similar in eyewear accommodation and functionality to that used on the old Red Wing Viewers. The Cedar Edges's large plastic lenses were good  in 10 out of the 10 last scopes which came through here.

* Alan Lewis makes the "MagniView Orthostereoscopic stereoscope": a noseless, shorter focus tech 'scope in an otherwise beautifully traditional wooden format. It has both inter-ocular (optical centers distance) and vertical centerline adjustments. Short of a Keystone-Mast ophthamological table scope, this is the best scope you can buy (adjusted correctly). The stronger lenses work well, especially with medium format transparency pairs, because they're achromats (color corrected, to eliminate high contrast fringing).


Stereoscope Design Considerations:

* The intended viewer geometry for classic (Holmes-Bates-Keystone-Society) format 7 inch cards (by those who gave it any thought at all), used 200mm (5 diopter), non-achromatic, plano-convex lenses with optical centers fixed at 85mm to 89mm of separation. That geometry worked great.  It still does.

That optical centers dimension has very little to do with the distance between your eyes, by the way. It's consequence is that your eyes will usually "toe in" on an average view with its 76mm between the frames (the "stereo window") and perhaps up to 79mm between details in the images. That toe-in anticipates the tendency of people to "look near" when they know a viewcard is less than a foot away. It also anticipates that the average person will pull an interesting viewcard in as close as he/she can comfortably focus, which proportionately reduces the effective optical centers separation down toward the actual inter-pupilary distance of your eyes --which averages 65mm.

Normal reading distance is about 14 inches (356mm) --which is as close as a person (on average) cares to comfortably hold a printed page. Eye-wise, that's about the same as pulling the stage-and-viewcard in to a distance of only 5 inches --instead of the full 8" focal length of a standard stereoscope's lenses. On average, the effective optical centers of a standard stereoscope will be reduced (say) 87mm to 75mm, which also happens to be the comfort limit, at which point your eyes' lines of sight start having to everywhere diverge in order to fuse the two frames of an old print pair stereograph.

* I don't believe that this stereo-optical geometry was worked out by some founding genius of the stereoscopic industry. It's rather a happy, "meant to be" result of using the shortest practical focal length lenses (out of deference to photographic resolution and chromatic aberration), splitting a single lens into halves (and then squaring the halves) to make a matched pair for a stereoscope, turning the thick sides out, and placing them far enough apart such that most everyone's lines of site are unimpeded as their eyes orbit across the visually fused pair of a stereograph.

* If anything, modern photographic resolution is a tad worse than were old contact printed, black and white viewcards of the past. I've measured 10 line pairs per millimeter (once almost 14) in the good antique views, whereas my best color work (a Rodenstock lens at the f/5.6 sweet spot in a Beseller dichroic color head enlarger) ran a film-to-print throughput of 6 to 8 line pairs per mm (up to 400 "DPI"), which is twice the assumed resolution of a good larger format (8x10 inch, say) photographic print. (This all works backward to assumptions about a camera's smallest "circle of confusion" and a practical "depth-of-field" to work with.) I therefore suggest that one stay with 8 inch (200mm, 5 diopter) strength lenses in a standard stereoscope, and no less than 6 inch lenses in a stereoscope or viewer meant for a 5 inch wide card (with a European/Japanese type medium format print pair).

* Commercial, mass-produced antique viewcards were die cut to fixed dimensions, therefore corresponding left-right points in the distance ("homologous points at infinity") had to float apart when close-up subject matter was included. Separation distances in such views could reach well over 80mm, so the optical centers spacing of a standard stereoscope is often needed --and with the card near full focal length.


Other Services:

* One of my former Stereosynthesis competitors (in The Netherlands):

Publications & groups

* Join the National Stereoscopic Assn. and read Stereo World, a first class magazine. Visit the new NSA web site. Learn all about stereoscopy and those doing it. Contact the NSA at PO Box 14801, Columbus, OH 43214

* The Stereoscopic Society, a correspondence association devoted to the making and sharing of modern stereo images, is associated with the NSA (which you must first join).

The SSA has been circulating each other's print pair views in the same format (along with other newer formats and media) for over 100 years.  A stereograph made in the 19th Century will fit into and view nicely in a stereoscope made just a few years ago. Often we discuss and debate the same subjects and techniques which concerned those early members of what use to be called the SSAB: "Stereoscopic Society, American Branch".  Here's an old circuit entry of mine.

--and the verso, which carries the maker's comments and any view data.

Circuit member comments (2 of 12), which are written on the "sleeve"/envelope which holds each view card:

> "Quite pleasant to view. Your remarks make me think you never owned a good dog!!  --Sadness, Jaded." {Bill W.};

> "Wow! --what stereo does for this! I love it. (Could be a moon of Jupiter.) I appreciate the sadness observation --one has to ponder. Pleasure is for the moment (like viewing this stereo view) --and the long range point, for us, seems to be the pointlessness. I see no contradiction between Craig's comments and owning a good dog (or cat!). They can and do co-exist. I do like this picture --what a philosophy initiator." {Bill P.}

* You might also join the International Stereoscopic Union and read their journal: Stereoscopy.

* And then there's the mother of us all: Britain's grand old Stereoscopic Society at:


I trust that none of us are cabooses on this train:!
End of the original home page

(Second edition, version 1993.5 + 07.0 revisions)

revised: 11/18/2008b


composed in Netscape-4.7, 800x600 prime, no cgi, java, or frames

This short work is intended for anyone interested in stereoscopic pursuits, but particularly for those who are trying
to create stereoscopic images. We hope that the words and phrases to be found here will become useful tools rather
than obstacles in your approach to "3-D" imaging.

We stress that this is a compendium of terms that we have found useful, confusing and/or interesting; while we have
tried to make it accurate, we do not represent that it is complete or of great scholarly depth. Some entries are long,
because we found the subject interesting or we knew a lot about it; some are short for the obvious other reasons!
We have tried to keep the tone conversational, rather than strive for uniform and rigid style; we've not felt ourselves
above an occasional wise-crack. Additions, corrections and improvements are always welcome --- we see ourselves
as editors rather than authors.  (Glossary is available via diskette or e-mail.)

* ANSI: American National Standards Institute.  See next entry.

* ASA: (1) American Standards Association. Although the expression "ASA" is still applied to U.S. film
speeds, the "American Standards Association" changed its name to the "American National Standards Institute" in
1969. Their standards are referenced by ANSI numbers such as "PH3.11-1953" (which describes the 5p format used
in cameras like the Stereo Realist and the Kodak Stereo 35).
  (2) As a film speed, it now appears in conjunction with the European DIN number (see) in the format
"100/21"" which, as such, is the "ISO" speed. Relative film speed is proportional to the ASA value.  Absolute film
speed is determined by a formula which in turn describes the judgment of a panel of
experts who have been shown the results of carefully controlled trial exposures.  If you don't like the results of
using the prescribed speed, use another and term it your "EI" or "exposure index.  Photographers often prefer to
use higher EIs for transparency films (to prevent color wash-out) and lower EIs for negative films (to ensure
adequate negative density).

* Accessory lens(es): Lenses that --as with planar cameras-- enable the stereo camera to focus and/or converge
closer (see: "Angle lenses").  Close-up lenses allow close focusing without the complications of excessive lens
extension, need for exposure compensation, and the like.  Other accessory lenses include those which alter the angle
of acceptance, producing in effect modest wide-angle or telephoto effects.

* Accidental Stereo Effects: Those stereo effects encountered by --for example-- fusing two postage stamps with
printing irregularities or encountering a pair of photographs in which there has been incidental lateral displacement
between the two exposures.  Sometimes called a "found stereo" by analogy to that venerable genre, the "found

* Accommodation: The refocusing of the eyes as their vision shifts from one distance to another.  When using a
stereoscope or "free-viewing", accommodation is uncoupled from "convergence"; those two processes are normally
linked to one another as a reflex.

* Achromatic (lens): Lenses designed to avoid chromatic aberration.  Simple one-element lenses and prisms, when focusing rays of "white" light can't bring the rays to a single point (or image made up of points).  Instead, a family of images (a blur) consisting of differently colored versions of the image/point(s) are created.

An achromat brings the main colors contained in white light to a common sharp focus.  This is achieved by having two or more lens elements, which differ in shape and/or refractive index, such that their chromatic aberrations tend to cancel each other out.  For example, a mildly diverging (minifying; minus-diopter) lens of high refractive index may be placed in front of a stronger, converging lens of lower refractive index.  The red end of the spectrum will be diverged more (than the blue end) by the first element, but also converged more by the second one --- if the balance has been well chosen, all colors will focus at the same place.

* Actual image: An optical image which is "actual" in the sense that it can be shown to exist by putting a screen
at its position and seeing it in projection.  It is sometimes also called a "real" image.  The image in the camera at
the film plane is an example.  (As distinguished from a virtual (see) or "Space" image.)

* Acuity: See: "Stereo acuity.

* Aluminum Screen: Usually also with a "lenticular" surface (diamond pleated so as to disperse light back into
the audience), the aluminum coating preserves the polarization of the two beams from a stereo projector.  A white
mat or glass beaded screen won't.  For rear projection, simple ground glass or special lenticular glass screens (ie:
actually micro-lensed, and for dispersion) can also preserve polarization.

* American stereoscope: See: "Holmes".

* Anaglyph: A stereogram in which the left and right images are superimposed but printed in complementary
colors (often red & blue-green).  It is decoded and viewed by placing correspondingly colored filters over the eyes.
The most practical form of stereo illustration for the printed page.

* Analyzer: See: "Decoder".

* Angle lenses: Supplementary lenses for a stereo camera used for close-ups. They both focus and converge the
camera's design window to a closer plane. A single large lens covering a pair of camera lenses will serve this

* Aperture: Any optical opening such as a camera iris or that at the back of a camera that masks the film and
determines the frame format.

* Auto-stereogram (graph): A stereo image that requires no auxiliary device or technique to be viewed (e.g.:
Nimslo lenticular prints).

* Axis: See: "Photographic axis," "Optical axis," "Visual axis," "World War Two, Major Alliances of.

* Bands: Ghost zones seen at the sides of an incorrectly trimmed/masked view.

*  Base: Usually understood to be the distance between the left and right lenses when a scene is stereographed.
  In this case, "stereo base" is roughly equivalent to the term "stereo displacement, although stereo displacement is sometimes expressed as an angle (see illustration), especially with medical X-ray stereo pairs.

It's the author's opinion that stereoradiograms, made by grossly rotating the patient between exposures are normally terrible. Were they made by means of laterally shifting the plates and/or the X-ray head, less frequent resort would have to be made to the expensive apparatus and their dedicated rooms/staff for advanced techniques such as magnetic resonance imaging (MRI).

b = stereo base; d = distance (lens nodal point to subject). Normally the camera's optical axes are parallel (although the "photographic axes" usually meet at the camera's built-in "stereo window").

Sometimes the subject gets slightly rotated on a turntable or rocker (hopefully, 3 degrees or less) between exposures, which are made with a single lensed camera (a technique often used in stereomicrography). If a small angle of rotation is used, the results bear some resemblance to that of a camera base of "b" divided by "d" (above illustration) --which gives the same angle in radian measure, or b/d times 57.29 --to get that same angle (of rotation) in degrees. More formally: angle of rotation = 57.29 (arc-rad [b/d])  --up to 3 degrees (or so).

A number of 3D movies have been made using cine cameras in which two lenses are adjustably "toed in" (for the best stereo window), as well as being displaced left-to-right. Both toe-in and rotation introduce registration problems and depth distortion in some proportion to the angle/s used.  See discussion under "Keystoning".

* Bates, Joseph: The man normally credited with producing the first of the classic American ("parlor")
stereoscopes, complete with a hood and an adjustable stage/card holder.

* Beam splitter: (1) An optical element that reflects and passes specified percentages of the light rays striking it.
For example, a beam-splitting prism is often employed in a microscope to allow viewing of the image through the
eyepiece(s) at the same time one is photographing it through a separate upright tube.  The old Canon "Pellix"
camera used a pellicle-mirror-type beam-splitter instead of a moving mirror, to allow SLR function without mirror
"slap"; this technology has recently been improved, and reintroduced in the Canon EOS-RT.  (2) A "stereo
attachment" (see); technically, most prismatic or mirror stereo attachments are more properly termed image splitters
or frame splitters, as they do not split an individual beam into components. The difference in light path between
the two devices is illustrated below.

* Binocular instrument/viewer: Any 2-lensed viewer, stereoscope, or a device for viewing a planar image with both eyes.

* Binocular vision: --implies, but might not refer to stereoscopic vision --which requires the healthy function of
a discrete area of the brain which sorts out relative parallax differences between the eyes.  See the "Cyclopean",
"Stereopsis", and the preceding entries.

* Brewster, Sir David: A great man of many accomplishments among which was the invention of the kaleidoscope
(1816) and the lensed stereoscope (presented in 1849, and published in 1856 in his The Stereoscope).  This he
referred to as the "lenticular" stereoscope as opposed to the earlier Wheatstone mirrored (but unlensed) stereoscope
(which see).  He carefully described the use and collimating nature of off-axis or prismatic lenses, particularly the
use of lens segments ("semilenticular" elements) for such purposes.  Consequently, all lensed 'scopes can be referred
to as "Brewster stereoscopes", whether full or semilenticular, but a fully lensed stereoscope (whether or not used
off-axis) is frequently referred to as a "Claudet" 'scope.

* Camera axis: See: "Photographic axis.

* Cancellation: The mutual extinction of the unwanted images (i.e.: no vestigial "left" image should be seen by
the right eye) in a stereo viewing system where the presented image is a coded composite of both the left and right

* Carbutt, John: The first production 35mm camera (the "Homeos") was a stereo camera and stereoscopy
preceded photography itself; thus, it is only fitting to note that the innovation and first use of dry plates and
celluloid film was in the field work of the pioneering stereographer John Carbutt --not, as commonly believed, by
George Eastman and the Kodak labs.  (See: John Carbutt in On the Frontiers of Photography by Brey.)

* Cardboarding: The characters in hand-drawn stereo cartoons look as though they are cut out of cardboard.
Sometimes views stereographed from life also convey this impression, especially if there is "squeeze" distortion
and/or if there are few distance cues intervening between major subjects.  This impression of discontinuous depth
is called "cardboarding" in stereographer's jargon.

* Chip: (jargon) One of a separated pair of transparencies (usual) or prints (occasional). The term probably derives
from the small slide frames of ViewMasterTM reels. Sometimes this is also called a "frame, although it causes
confusion with other uses of that word.

* Chromatic aberration: The degree to which light is bent when it passes at an angle through a transparent material such as glass is not the same for all colors. A simple lens will therefore not focus white light to true lines and points, but rather to a family of colored images blurred together.  Different colors will find their sharpest focus at different distances from the lens.  When a lens is used off-axis --as is the case with the common print stereoscope-- this effect may be particularly prominent, and notices as a colored fringe around a seemingly sharp image. However, the degree of prism effect in such lenses (= 6 diopters) is such that the effect is usually not objectionable. Compound lenses may use elements of different refractive index to offset this aberration (See entry under "Achromatic lens").

* Chromatic stereoscopy: An effect resulting from color aberrations in viewing lenses (or even in the eyes) which
produced stereoscopic effects in both stereo and planar color images.

* Circle of Confusion: (1) The smallest image that a camera's lens can form of a point of detail.  (2) The smallest
such image of a point of detail that is assumed to be acceptable for the calculation of depth of field, depth of focus,
"hyperfocal "distance and related indices. This is often taken as 1/1000 inch, and standard depth-of-field tables are
based on that assumption. A smaller circle of confusion assumption (which may be appropriate for very high
resolution lenses and films) will yield shallower depth-of-field estimates than those provided by the conventional
tables; a larger circle of confusion (which may be appropriate for soft-focus portraiture) will yield deeper
depth-of-field estimates.

* Claudet, Antoine: was a Frenchman, but privileged to be Queen Victoria's court photographer and a
 contemporary of Brewster and Wheatstone.  He operated a stereoscopic portrait studio and produced (4)
 viewers with complete (i.e. not "semi"lenticular) viewing lenses.  He was probably the first to recognize
the distortion caused by the use of long-focus camera lenses "compensated" with a wide base.  This causes a
combination of two distortions, "Squeeze" (contracted perspective) and the special distortion of stereo minification.
This combined distortion is now often called by the jargon term "PePax", a contraction of perspective and parallax
coined by Herbert McKay (see) many years later.  This is also sometimes called "frustum effect.

* Co: Gender-nonspecific pronoun: co (nominative), cos (genitive), com (dative/accusative)

* Colardeau Progression: In a standard 5-perforation format camera (Realist, Kodak Stereo 35), the lenses are separated by three frame-widths, and the film is advanced by a constant two frames.  This results in stereo pairs separated by two unrelated frames on the film (a clever idea). This progression sequence was designed by L.J.E. Colardeau, who with J. Richard produced in 1914 the Homeos stereo camera using it.

The advantage of the Colardeau progression is that the film travels the same distance each time it is advanced,
allowing a much simpler and more reliable film advance mechanism.  The minor disadvantage is that the individual
frame width is limited to one third of the distance between the centers of the left and right images of a given
exposure. For example, the Realist had its two images on 70mm centers; thus, the Colardeau progression required
that the frames be no more than 23.33 mm wide (so if you ever wondered how the Realist, Kodak Stereo and several
others all ended up with 23x24 mm frames, that's
the "scoop").

* Collimation: When the distance between the centers of a stereoscope's ocular lenses and the separation of the
image pair placed in it are equal, and when the images (or view) are (is) placed at the full focal length, the lenses
of the stereoscope act agreeably as "collimators" for the "homologous" points of the image pair.  This means that the
interpupillary distance of any user's eyes is automatically accommodated without adjustment.  It also means that one's
eyes need not be perfectly level with the view (a great convenience in viewing). (Accordingly, gravity-leveled
eyewear has been proposed for viewing side-by-side pairs presented on a fixed screen at close range.)

* Convergence: The meeting of lines of sight through the eyes or of light rays through an optical system at a
common target point.  Sometimes this is expressed as absolute convergence --the angle subtended by the converging
lines at the target-- but also as half that angle (the convergence for each eye rather than for both) and as relative
convergence.  See: "Deviation".

* Convergence micropsia: Minification (image appearing smaller than it ought) resulting from the exaggerated
parallax of hyperstereo.  This is sometimes called "miniaturization" in stereographers' jargon; that term, however,
is more properly applied to making an object physically smaller, rather than making an object appear smaller.  See:
"SILO Effect".

* Copilia quadrata: Worth a mention in anyone's glossary, the female version of this pinhead-sized aquatic creature was first described in 1891 by Seliig Exner.  Between 1963 and 1972 its bizarre optical equipment (and mating behavior) was recognized and examined by Richard Gregory (see his Odd Perceptions).  Copilia is quite transparent and the entire width plus more than half her length is devoted to the support of a binocular visual system! Even more striking is her animal kingdom exclusive: she has interior single element photosensitive arms that linearly scan the image pair and "flyback" (Television style) to rescan another line of the image pair!!

* Corresponding points: See: "Homologous points".

* CraigLo Camera: A minor modification of the Nimslo camera consisting of narrow inserts, glued to either side of the center focal plane septum (ie: between frames #2 and #3) --such that the operator of a manual film printer is encouraged to jog the film --enough to neatly and properly print the outside pair of the quad --plus enough of the inside pair to fill the printer's 8 perforation (35mm "full frame") aperture mask. (This modification is probably of no avail for today's (2005) fully automated processing machines. Consider using recent editions of the "Loreo" or "Snap 3D" stereo cameras.)

* Crossed-eye viewing: See: "Free-viewing".

* Curved cards: Curved cards became popular late in the last century. Such cards are stronger, protect the image pair, and
"preëmpt" random warps about either axis of the view card.  It has been further suggested (in an interview of a Keystone
engineer by Prof. Max Kent, of Dayton, Ohio) that the curve helped match the view's surface to the field curvature of the
stereoscope's lenses.  In Stereo Views, author John Waldsmith reports that curved cards were first sold to the public as a
gimmick, claiming that they had a superior depth content.

* Cyclopean: (From Cyclops, after the [Greek] mythical one-eyed giants) (1) Pertaining to a cyclops.  (2) Metaphorically,
pertaining to the fused stereoscopic image, as opposed to a non-stereoscopic image or to the stereo image as its two or more
planar component parts.  Thus:

* Cyclopean axis: The apparent axis of view of a stereoscopic image; generally, the line bisecting and coplanar with the
angle made by the two converging optical axes of the eyes (or the line parallel to and midway between the two optical axes
of the components of a strictly orthostereoscopic system such as a traditional stereo camera).

* Cyclopean center: (1) The area of the brain which perceives a fused stereo pair as a single, three-dimensional
image....the "mind's eye," if you will. (2) A social hall for one-eyed people, of little interest to stereographers.

* Darrah, William C.: Author and publisher of the definitive The World Of Stereographs in which views and makers
are compiled with a worldwide historical scope.

* Decoder: See: "Viewer.

* Depth of field: Although a camera lens truly focuses at only a specific distance, objects closer or farther than that specific
distance may be in very acceptable focus.  This range of acceptable focus is known as depth of field.
Once the acceptable criteria for sharpness have been set (generally as a maximum "circle of confusion [q.v.]"), the depth
of field is determined by the lens aperture ("f-stop") and by the ratio of image-to-object size; the latter is determined in turn
by lens focal length and the distance from the camera to the object.  To maximize depth of field, one would use a small
lens aperture (large "f-stop" number), a short focal-length lens, and a long distance from camera to subject.  In
stereography, one of the seldom intentionally-broken "rules" is that of keeping everything in the view in sharp focus.  One
expects to be able to focus at different depths in a stereo image, and it can be very distracting if it's not possible --the use
of shallow depth of field for effect in stereo rather often backfires.  Comment: It is commonly held that a short focal length
lens gives greater depth of field; that's really a half-truth.  If one takes a full-frame head-and-shoulders portrait with a 105
mm portrait lens at f:11, then takes another --also full-frame head-and-shoulders, same image size --with a 35 mm lens at
f:ll, the depth of field will be the same in both photographs (though the nose will not be flattered in the 35 mm view).  The
35 mm lens will give greater depth of field if the distance to the subject is what's held constant, rather than the image size;
in that case, one pays for the increased depth of field with a smaller image size.

* Depth of focus: This is the same phenomenon as depth of field (see), but at the other end of the optical axis.  In other
words, it's the acceptable error range for film positioning. If a lens does not bring the image to focus in a true plane at the
film-plane of the camera (as when using a non-macro-corrected lens for macro work), edge sharpness will be enhanced
by the use of a smaller lens aperture to maximize depth of focus.

* Depth perception: See "Stereopsis".

* Deviation (sometimes "deviation range"): In stereoscopy: the range of convergence within a view (see also
"MiRF" and "Mer"), but only the angle turned by one eye between near and far points.  Ophthalmically: deviation (and
convergence) is measured in diopters (which see). 2.5d (=1.43 degrees or the deviation for an apparent range of depth
from 4.3 feet to infinity) has been suggested as a limit for good stereographs.

* DIN: Deutsche Industrie-Norm A system of standards, analogous to that of the ANSI (see).  For film speed, the
DIN numbers are different from the U.S./ANSI/ISO/ASA numbers in that the scale is logarithmic rather than linear.
Thus, for each doubling of film speed, the DIN rating increases by three degrees.  ISO/ASA 100 = DIN 210;
ISO/ASA 50 = 180; ISO/ASA 200 = DIN 240

* Diopter: (1) The power of a lens found by dividing its focal length into 1 meter (very useful for dealing with
optical systems).  (2) The power of a prism (or the off-axis prism equivalent of a simple lens) found by tracing the
deflection of a ray passing through it.  The actual deflection (say: to the right on a screen beyond the lens) as a
percentage of the distance to the screen is the prism power in diopters (=100 times the tangent of the angle of
defection).  (3) A measure of the convergence or deviation of the eyes.

* Diplopia: Double vision.  Normal to all images visually perceived as being closer or further than the convergence
point of the eyes.  Abnormal in vision when image fusion (and stereopsis) can't be achieved.

* Disparate images: A pair of images that fail as a stereogram due to distortion, poor trimming/masking, mismatched camera lenses, or the like.

* Divergence: The opposite of convergence, as when the eyes' lines of sight "toe out" from each other.

* Dynamic stereo diplopia: The active convergence and divergence of the eyes along planes of depth during stereoscopic vision.  If a stereograph or a scene in life is viewed for only an instant, or if the eyes be stilled in their orbits, there is no stereo vision.  Like the other senses, the experience of stereopsis depends on change and refreshment.  (This is but one side of an old debate that started between Brewster and Wheatstone and carries on to this day.)

* Eclipse system: A stereo viewing system in which the left and right images are viewed alternately in rapid
sequence.  Persistence of vision causes the images to be blended in the mind's eye.  A viewing device decodes or
separates the images by alternately interrupting the vision in each eye in synchrony with the screen sequence.  This
is the probable future of 3-D TV; current devices use electroöptical shutter spectacles at a field rate of 120 per second
(= 60 interlaced frames).  The technique has also been used in cinematic and still projection by using mechanical

* Elmo (attachment, system): An over/under image splitter stereo attachment. As the name implies, this attachment
was made to fit Elmo brand 8mm motion picture cameras and projectors.  It is similar to the Savoye device in that
it places stereo pairs onto a single frame in bottom-to-bottom relationship, but uses only front-surface mirrors to
accomplish this.  Elmo --of Japan-- never officially exported this device to the U.S., reportedly due to a concern that
it might damage the reputation of Japanese manufacturing (i.e. Americans were thought not to have the patience and
discipline to adjust and use the system properly).

* Emde: a brand of die-cut aluminum slide mounting mask; the product line includes normal (RealistTM-format)
stereo masks, masks for European format stereo cameras and masks with smaller apertures for the correction of stereo
window in close-up views.

* Esophoria: A tendency of the eyes to converge at rest.  This is not as common a condition among normal people
as is a slight degree of exophoria (see). This is advantageous in free-viewing stereo pairs in crossed fusion (reversed
left-for-right), but disadvantageous in viewing orthotopically-positioned stereo pairs.  Esophoria and exophoria may
be unmasked by covering one eye and fixing on an object; when the covered eye is uncovered, it will be noted to
have drifted and will have to correct its position to allow proper fusion; the subject will notice transient double

* Esotropia: An abnormal tendency of the eyes to converge.  This is basically the extreme case of esophoria (see);
the difference is that no cover-uncover or cross-cover test is needed to demonstrate it, and it may make it impossible
to achieve stereo fusion.  It may also lead to the underdevelopment of vision in the non-dominant eye, a condition
known as ambylopia ex anopsia (and sometimes called "lazy eye" in common parlance).

* Exophoria: A tendency of the eyes to diverge at rest.  Many --- perhaps most --- people have a slight degree of
exophoria, such that a very small amount of convergence from the rest position is necessary to view objects at
infinity.  This is advantageous in free-viewing orthotopically-positioned stereo pairs (not reversed left-for-right).
People who have a bit more exophoria than others tend to find such free-viewing easier, and to be able to free-view
images at a larger stereo separation.  This is a disadvantage, however, for the free-viewing of stereographs in the
cross-eyed mode.  Esophoria and exophoria may be unmasked by covering one eye and fixing on an object; when
the covered eye is uncovered, it will be noted to have drifted and will have to correct its position to allow proper
fusion; the subject will notice transient double vision.

* Exotropia: An abnormal tendency of the eyes to diverge. This is basically the extreme case of exophoria (see),
the difference is that no cover-uncover or cross-cover test is needed to demonstrate it, and it may make it impossible
to achieve stereo fusion. It may also lead to the underdevelopment of vision in the non-dominant eye, a condition
known as ambylopia ex anopsia (commonly called "lazy eye").

* Extended legend: Information provided on the reverse side of a stereocard, which extends the simple
title-and-maker description characteristically provided on the face of the card.

*  Ferwerda, Jacobus G.: Author of The World of 3-D, (Second edition: 1987).

*  Five-perforation format: See: "Format."

*  Flicker projection: See: "Eclipse system"; not to be confused with the vigorous tossing of a small bird.

*  Floating edges: Top, bottom or side edges of a view which do not agree in location between the two images of
a stereo pair.  Such edges are said to "float," because of the sense they give in fused viewing that their position is not
fixed, or that they are in the wrong place with respect to the subject matter.  Often the "floating" appearance results
from having a "stereo window" which is not all in the same plane, or which is located behind subject matter which
is in turn close to the edge of the view.  See the discussion under "Stereo window".

* Format: (1) The dimensions of an image, such as those on a strip of film; for example, the 24x36mm full-frame
standard format for 35mm planar cameras. (2) Reference to format by associated features.  For example, the
23x24mm image size may also be termed the "5p" format, because there are five standard 35mm film edge
perforations (sprocket holes) per frame.  (3) In stereography, "format" can also be a reference to the separation of
"homologous" details at infinity in a type of view (i.e.: "78," "80," or "82"mm for print views); the overall
dimensions of the unmounted view (i.e.: European "6 x 13" centimeter); mounted view ("7 inch" for American print
views); or separately mounted image pairs ("[2x2]x2" or "2x2" for paired standard mount "full frame" [35mm 8
perforation] transparencies).

*  Frame: An individual image on a strip of film.

*  Frame notch: See:"Witness notch".

*  Free vision (or free viewing): Usually understood to mean the fusion of adjacent left and right image pairs by the
ability to either diverge or hyper converge the eyes (while they remain focused at reading distance) in order that the
side-by-side images be seen in register as a single fused view (ie: no use of a viewing device).  This has been
seriously proposed as a skill to be learned by the public at large for the purpose of viewing stereoscopic image pairs
in mass media publications (see "Herbert McKay").

* Frustum effect: Distortion creating images shaped like a frustum (the term may apply to any solid which has been
cut by two parallel planes, but is most commonly used to describe a truncated cone).  See: "Keystoning", "Claudet".

* Fusion: The visual registration in the mind ("Cyclopean center") of the images perceived in each eye.

* Ghost image: (1) A transparent image.  Thus: an image that can't be satisfactorily fused or directly seen, such as
the "bands" that appear at the sides of an incorrectly trimmed/masked view.  (2) The "alternate" images that are
insufficiently canceled by (say) a decoding viewer of a composite view.

* Grapho(stereo)scope: The "Graphoscope" has no stereo lens pair; only a large single element for examining flat
prints.  See "Stereographoscope" for the item you're seeking.

* Grid(stereogram): See: "Parallax stereogram"

* Hammerschmidt Jig: (1) A dance so lascivious that it has been banned in nearly every civilized country.  (2) A
turntable stage for stereography of small objects, by which two sequential planar images are made with rotational
displacement to create a stereograph. The jig rotates the light sources through the same angular displacement as the
subject, so that the shadows remain the same in both images.  See: "Rotational displacement stereography.

* Heterotopic: Not in the customary place or orientation. The opposite of "orthotopic" (see).  An image designed
for cross-eyed fusion or reversing stereoscope viewing is a heterotopically-positioned view, while one designed for
a conventional Holmes 'scope is an orthotopically-positioned one.

* Holmes, Oliver Wendell (Sr.): A physician and author who, in 1859, is said to have reduced the then expensive
and box-like Brewster stereoscope to its bare elements and attached them to an open skeleton frame (see: "Bates").
(Oddly: others say he added only the hood and sliding stage, but his surviving hand made model shows neither.)
Holmes was a frequent contributor of essays to The Atlantic Monthly, many of which celebrated stereography.  His son became (U.S. Supreme Court) Justice Oliver Wendell Holmes (Jr.).

* Holmes Library: The National Stereoscopic Association, its members, and Eastern College at St. Davids,
Pennsylvania support a fine and growing library and museum of stereographica for research. (In 2006, without announcement, consulting the NSA membership or past donors, the board of the OWH Library sold off the collection --!)

* Holmes-Bates Stereoscope: This is the classic, "standard", "American", skeletal, affordable, mass-produced "parlor 'scope". See also "Lenticular stereoscope".

Although the Red Wing Viewer (which see) is the only standard stereoscope known to the Glossary's authors to have published specifications, most standard 'scopes were and are similar in their designs and geometries --allowing for the fact that people's faces and eyeglasses are significantly larger now than they were 80 to 150 years ago. This is because a standard 'scope's lenses were traditionally made by bisecting a single 60 to 70+ millimeter diameter plano-convex lens, squaring them, then turning and mounting them into the 'scope with the thick ("base") edges outward. Necessarily, the outer edges have to be far enough apart (about 3-1/2" or 90mm, reduced a bit by the lens cell retainers) to accommodate the lines of sight from the pupils of one's eyes as they orbit from left to right --in order to see all of a (up to 3" wide each) stereo print pair on a 7 inch wide card. Old scopes might have a lens span of only 3-3/8 inches or 85mm.

That span between outer lens edges (which might be hidden as mounted) is the "optical centers" (span) of a stereoscope. With a card placed at the full focal length of its lenses, the span between optical centers is the limit of the distance between "homologous points at infinity" (which see) of the viewcard (as trimmed and mounted). In practice, however, people like to "crowd in" on a viewcard when the stage of a stereoscope is adjustable. They haul the viewcard in closer to the lenses in order to "see more", to make the view bigger, and often to accommodate slightly myopic vision.

However, when a card is viewed at less than the focal length, the "prism power" of its base-out lenses --that is: the lenses' ability to diverge the user's lines of binocular sight, is proportionately diminished. Consequently, best practice is to trim and mount view cards to no more than about 3-1/4" (82-83mm) of maximum separation (see: "Homologous points") --for use in a standard stereoscope intended for 7 inch wide cards.

While much is to made about separations, the most critical specifications for viewers and viewcards are the tolerances to which the lenses, stage, and cards are held with respect to the vertical registration of the images. Best practice is to keep the apparent discrepancies in a fine binocular instrument to within 1/4 minute of arc (15 seconds, or about 1/100mm at 200mm to the view card!), but when working with the wood, paper, and mat board of print-pair stereography, you're doing very well to bolt it all down to within half a millimeter over-all. We learn to use/tolerate a little "aphoria" (which see) and almost unconsciously correct to best eye comfort by torqueing (as necessary) on the 'scope, viewcard and stage while viewing. (Note: our eyes are normally biased with a bit of aphoria --which means one eye looks a tad higher than the other. That way the muscles of our eyes work under a wee bit of tension to correct it to true, with no free-floating "backlash".)

* Holography: A technique for producing images which convey a sense of depth, but are not stereograms in the
usual sense of providing fixed binocular parallax information. This is accomplished by the recreation of (spectrally
restricted) wave fronts of light that appear as if they emanated from the subjects that were holographed.  It is to date
impractical for all but lab-produced examples of this process, since the coherent light source, subjects, and
glass-plate-supported microfine-grain emulsion must be held extremely steady in their spatial relationships, free of
vibrations or out-of-system illumination.  Somewhat greater flexibility is possible with the use of pulsed high-energy
lasers, but cost and safety considerations have limited application of this method. Despite these limitations, and the
inability to present accurate color, the images may sometimes be quite striking. See discussion under "Space Image.

* Homologous distance: The distance between two "homologous points" (meaning the same --except for being the
left and right versions) in a stereo view.  The maximum separation of such points in a view's distant subject matter
are often said to be "the separation" of the view, and held to some standard.  The optical centers of the lenses of a
stereoscope (or free hand lorgnette) are separated by this distance or more.

* Homologous points: See: "Homologous distance".

* Hyperfocal distance: For a given lens used at a given "f-stop" with the expectation that it will resolve point details
on the film no larger (ie: fuzzier/blurred) than a "circle of confusion" of a given diameter: --a focusing distance can
be determined for which all subjects from infinity to 1/2 the focus setting will be "in focus."  In other words (and
numbers): take the square of the focal length (in inches), divide that by the product of the "f-stop number" (that you
plan to use) *times the diameter of the smallest detail you want your lens to be able to resolve on the film (in inches).
The answer (in inches) is the hyperfocal distance.  It's easier to use the DOF indications on your focusing scale, but
the resolution figure has then been chosen for you (usually .001 inch).

* Hyperstereo: The effect of enhanced depth and reduced scale of a scene introduced through use of a camera lens
(pair) separation ("lens base") wider than normal (65 to 70 mm).  (See entries under "Stretch" and "Squeeze" for effects caused by disparities between taking and viewing distances).  Very large camera lens separations are used to reveal depth in architectural and geological-scale scenes.  The perception of a hyperstereo image is described by the terms "SILO effect," "convergence micropsia" and "Lilliputianism" (all q.v.). "Miniaturization" more properly describes the actual physical reduction of an object, rather than a mere reduction in apparent size, but this term is also often applied.  "Puppet theater effect" (see) is caused by resorting to a perceived image pair infinity that is significantly less than visual infinity.  Studies by David Burder suggest that the static nature of still stereography does not completely serve one's visual expectations if only the "orthostereo" (see) conditions of stereography (1-to-1 relationship between lens and eye separation; 1-to-1 relationship between viewing and taking distances) are employed.  This is because when we look at a scene in life, our heads and bodies are in motion --perhaps even involuntary motion-- as we attempt to explore the parallax changes in a scene caused by changing our point of view. Mr. Burder's tests concluded that modest hyper (and stretch) enhancements to a view that are in proportion to its scale were generally appreciated and considered "normal" by general audiences, and they have often been used by producers of  commercial stereo views.

* HyponarTM: A brand of parallel-axis stereo lens set which replaces the lens of an ExaktaTM single-lens reflex
camera.  This produces a stereo pair which is reversed left-for-right (because the images are in orthotopic position
but inverted), so that a transposing stereoscope is needed to view them without remounting.  A similar device was
also produced under the brand name of KinDarTM

* Hypostereo: Stereography with a camera lens base (lens pair separation) narrower than normal (65-70 mm) is often
used for adult portraiture and close-up to macro/micro distance stereography.  A similar  effect (called "Squeeze")
can be achieved by enlarging the images and viewing a smaller portion with standard or shorter-than-normal 'scope

* Image splitter: A device mounted on the lens of an ordinary planar camera, which through the use of mirrors or prisms, divides the image and frame into two halves, which are the two images of a stereoscopic pair.  Sometimes called a frame splitter, and sometimes imprecisely called a beam splitter (see). Such devices have appeared under the Zeiss, Stitz, Franka and Pentax trade names, the latter two in production and fairly readily available as of 1990.

The devices usually produce a small degree of keystoning, which may or may not be noticeable in an individual view. Their advantages are modest cost, portability, the ability to use ordinary film processing services, and the ability without much fuss to mix planar and stereo views on a single roll of film.  The disadvantages are that viewers (O-Stereoscopes [q.v.l) for the resultant (18x24mm)x2 slides are scarce, and the slides can be projected only with similarly uncommon polarized (convergible) splitters (or by splitting them into their component half-frame transparencies); routine 3R or 4R prints into this format may be made into stereo cards, but either require a good bit of trimming (4R) or the individual frames are too narrow (3R) to use pre-cut masks, such as Q-Vu masks.  Because of the modest price, and the ease with which an occasional stereogram may be made, these devices may be excellent "starter" equipment for someone exploring whether he or she really wants to take up stereography.

This image shows a schematic of such a device, as well as a line outline of the appearance of a transparency made with one.

* International Stereoscopic Union (ISU): This is an international organization; its journal Stereoscopy is printed
in English.  Some of this glossary has its origins in the (old) "Technical Supplement" to Stereoscopy.

* Interocular distance: The separation between optical centers of a viewer (which may be adjustable).  (From L. oculis, eye; an ocular lens is one through which the eye views, as opposed to an objective lens.  If adjustable, the interocular distance of a viewer's eye lenses is often set such that the lenses' geometric center is equal to the distance between the optical axes of the eyes themselves, whereas they should be set to equal or exceed the infinity seperation of the mounted view slide or card.

In stereography, the term is often used to refer to the distance between the axes of the ocular lenses, which may not be quite the same as the distance between the axes of the eyes in a slide pair viewer, or grossly different in the case of a standard print pair stereoscope (for reasons of collimation [q.v.]).

{Again: it is a common error to assume that the interocular distance should agree with the interpupillary distance
of the observer.  It should be equal to or be slightly greater than the maximum separation of homologous points of the
view (in the case of a simple viewer) or such points of the image formed by the objective lenses.  See "collimation."}

* Interpupillary distance (IPD): The distance between the pupils of the eyes when vision is at infinity.  IPDs range
from 55 to 70 millimeters, but the average is usually taken to be somewhere between 63.5 and 65mm (2-1/2 inches).

* Inverse stereoscopic: The preferred (Soviet [of course, given that a "soviet" is a type of governmental deliberative assembly, one might question the political overtones of using the term in an adjectival sense to describe something which merely derives from the Soviet Union]) term for what is sometimes called "pseudostereo" (which see).  This is the sometimes confusing and at other times intriguing visual effect when the planes of depth in a stereograph are seen in reverse order.  Things far seem near despite their occultation by things in the view that were actually near (i.e.: what you "see" is impossible!).  An instrument called a "pseudoscope" was invented (and claimed by Sir David Brewster [away from Sir Charles Wheatstone] as of 1849 in his 1856 The Stereoscope).  This device produced the same effect in the observer's surroundings.  A simple pseudoscope may be made from two 90" prisms (held as "outside" or "Dove" prisms).

* ISO: See: "ASA"

* Ives, Frederic E.: See"Kromscop".

* Judge, A. W.: Author of Stereoscopic Photography in several editions.

* Julesz, Bela: While working at the Bell Telephone Labs with a background as a RADAR engineer (and a then
unseen future as a visual psychologist), Julesz created the first pairs of random element stereo pairs. Little or nothing
can be perceived in either frame of the pair but, when visually fused, stereopsis --and stereopsis alone-- slowly
reveals that the otherwise randomly placed elements are organized into homologous pairs that form patterns in
perceived depth.  This invention/concept and all its variations has ignited a formidable amount of research into visual
perception (lately indicating that the brain has a small area dedicated to stereopsis/parallax processing/analysis).  It
will not fail to ignite your own wonder at the processing of information that goes on in the mind, quite without our
volition or knowing direction!

See Julesz's Foundations of Cyclopean Perception, R.L. Gregory's Eye and Brain, and John P. Frisby's Seeing.
NSA member Gerald Marks produces very effective random dot anaglyphs using silk screen techniques.

* Keystoning: When the plane of a projected image falls on a screen that is not parallel with the transparency being
projected, the image "spills out" or widens at its further extents in the familiar "keystone effect".  The trapezoidal
screen image resembles the keystone of a masonry arch, calling to nostalgic memory the herald of the Pennsylvania
Railroad.  When the optical axes (plural of axis) of a stereoscopic projector are misaligned, the mutual keystoning
of the image pair can be very disturbing.  Similarly, when the plane of the film in a camera is out of plumb with a
building being photographed, the familiar "perspective distortion" of should-be-parallel-but-they're-convergent
building lines occurs in the finished picture. If two cameras are synchronized to produce a stereographic pair, AND
if they are "toed-in" to converge on a subject (at a finite distance from the cameras), the resulting pair will exhibit
mutual keystoning, and consequent depth and shape distortions; especially in the "macro" range, this may be enough
to make fusion less comfortable and/or to make the "window" edges appear less sharply drawn.  The same effect
--again usually tolerable, but not always-- is noted in image-splitter stereo attachments for single-lens-reflex cameras.
Gross departures from orthostereoscopic practice (say: the use of telephoto camera lenses) can produce "keystoning in depth," more properly called "frustum effect.

* Keystoning Distortion: This is an extension of the last entry and is based on a graphic revelation (below) and
article ("The End of the Matter", Series 2, Number 27, page 4) by Editor Michael Gordon in the ISU's Stereoscopy.
A glance at the below pair of stereograms should convince you that Mr. Gordon has settled the hash of many an old
adversary on the issues of "to toe in, or not to toe in" one's camera stations, --in order to establish the stereo window.
An extract follows:

"Curiously, the converged pair shows perspective but no increase in separation for the bottom (more distant) pole!
If you stereo-view (fuse) the images, you will see the oddity of the vertical line passing through both poles at the same
apparent distance.

The ISU globe at the bottom has both perspective and parallax changes showing that the bottom pole is indeed more distant than the top. If you stereo-view this pair, you will see that the parallel lines bisect the top pole, but not the bottom; this is correct behavior."

* Kromscop: (See Stereo World, Volume#15, #1) In the 1890s, Frederic Eugene Ives --a pioneer in printing
processes-- developed an amazingly well thought out system of color stereography using black and white emulsions
and compound transmission/reflection color filtering.  The Kromscop was the viewer and a self transposing stereo
camera was also available.  The system used 3 color separation transparency pairs of images in registration to recreate
a view called a "Kromogram."

* LEEP camera (system): A special camera that stereographed views of nearly 180 degrees of solid angle (2 pi
steradians) by means of special aspherical fisheye lenses forming images on conventional film.  This very distorted
swirl of an image pair was than viewed by the same kind of lenses to decode it into approximately the original world
view.  A belt was supplied to strap it to a tree or vertical standard, thus avoiding a forward tripod leg or two getting
into the view! Only three complete cameras and very few viewers were completed.  Not even the
inventor/manufacturer --Eric Howlett-- owns one.

* Lenticular: (1) Of or pertaining to a lens.  (2) Shaped like a lens.  This word has many uses, several of which
pertain to stereography: (a) A stereoscope which contains a lens --as opposed to one which used mirrors only-- was
called by Brewster a "lenticular" stereoscope.  (b) A lenticular grid is an oversheet with refracting vertical stripes
which may be used to view Autostereo (see) prints; (c) A lenticular screen (often "sliver"/aluminized) is a projection
surface made up of tiny silvered concavities or simple vertical grooves.  This type of screen disperses the light better
to the outside rows of the audience.  (A metallic coating also holds polarization of the light it reflects, allowing stereo
projection by the opposite polarization of the two images and the two viewing lenses/filters.)

* Lenticular grid: See: "Autostereo".

* Lenticular Stereoscope: (1) Any stereoscope which contains lenses --as opposed to one which uses mirrors only. Sir David Brewster called his lensed stereoscope a "lenticular stereoscope" and accurately described the optical nature of such 'scopes, whether full-lensed or half-lensed "semilenticular" types. Such 'scopes are properly called "Brewster stereoscopes".

The "American", or "Parlor", or "Holmes" or "Holmes-Bates" stereoscope for 7 inch wide cards is, therefore, a "Brewster stereoscope", even though that term is is most commonly applied to the closed box 'scopes that Brewster designed. See: "Holmes, Oliver Wendell (Sr.)" and the "Holmes-Bates stereoscope".

* Level: The stereographic community has a fetish for level horizons, even when the horizon can't be seen.  To
accomplish this, at least four stereo cameras (Kodak stereo 35, Revere 33, TDC Vivid and Wollensak) were equipped
with spirit levels visible in the viewfinder.  It is readily possible to correct mildly tilted horizons when trimming print
pairs by simply squaring to the horizon or a vertical.

* Lilliputianism: A stereographer's jargon term for minification through excess lateral parallax or "base."  See:
"Hyperstereo", "Minification", "SILO effect".

* "Litho": Properly, this refers to lithography, but it's a commonly used term in reference to any mechanically
printed image, such as the half-tone process.

* Loreo Camera: A very well thought-out design in which transposed pairs are placed onto a single 8 perforation (standard) 35mm film frame, such that they can be printed normally by any photofinishing machine. The film path is even bent, so as to preclude keystoning or depth-of field problems. Recent (2005) versions (sold by Berezin --see:

--use good glass mirrors in place of the often unsatisfactory plastic molded ones.

* Marks, Gerald: Creator of fascinating anaglyphs and stereoscopic exhibits in San Francisco's "Exploratorium."
Has been a visiting artist at the Massachusetts Institute of Technology.

* Mask: An opaque cover with apertures over a pair of stereo images.  The placement and size of the apertures
determines the location in space of the "stereo window" (see) with respect to the subjects in the view.  Trimming a
pair of stereo prints and mounting them appropriately will accomplish the same purposes.

* McKay, Herbert: Fellow of the Royal Photographic Society, author of Three Dimensional Photography, and
founder of the Stereo Guild.

* Mer (milliertem): A metric method of dealing with the small angles of deviation (which see) found in a stereo view or in life.  A base of 65mm is assumed and the actual nearest and furthest distances in meters contained in a scene (in life) are each divided into 1000.  The smaller number (zero in the case of infinity) is subtracted from the larger to get the deviation in Mer.  The value for 4 feet to infinity is about 800 Mer. (See MiRF)

* Minification: Making something appear smaller through an optical effect (minifying lens [q.v.] or exaggerated
lateral parallax [or "base"]).

* Minifying lens: A lens which diverges rather than converges light rays, with the result that objects viewed through
it appear smaller ("minified," "minification").  Its strength is measured in negative diopters (see) and it's the opposite
of a magnifying lens (magnification). Used in meniscus form for the correction of myopia (nearsightedness).  A
minifying lens may also be used to correct a fixed-focus lens to a true infinity focus (usually minus -0.25 diopter is
about right for this purpose), or to restore infinity focus when a lens has been fitted to a camera body thicker than
that for which it was originally intended.

* MiRF (milli-reciprocal feet): Coined by Craig circa 1985 and proposed as the English measure equivalent
of the Mer or 1000 divided by the distance in feet to the furthest subject minus the same for the nearest.  The distance
from 4 feet to infinity contains 250M (normal IPD [q.v.] spacing assumed).  The deviation between 2 feet and 4 feet
is also 250M, but if a hypostereo (see) base of 1-1/4 inch is used, the value reduces to 125M.

* Mirror viewer: See: "Wheatstone".

* Morgan, W.D.: Editor of the Stereo Realist Manual, 1954.

* Mount: A slide body or card used to secure, locate, and protect the two images of a stereo pair. Usually the term
includes any mask involved.

* Mounting jig: A device for locating, holding, and sealing pairs of stereoscopic images into or onto a common
mount.  Usually in reference to slide mounting, but also for mounting print pairs.

* National Stereoscopic Association: Headquartered in Columbus Ohio, the NSA is dedicated to the enjoyment,
study, advancement and conservation of the history of stereoscopy and stereoscopic images.  It has sub-regions across
the U.S. and has members around the world.  They are kept in touch by their excellent journal, Stereo World and
have annual conventions.  See also: "Stereoscopic Society.

* NimsloTM: The brand name, taken from inventors Dr. Jerry Nims and Alien Lo, for a stereographic system that
produces autostereo (see) prints having a very fine integral screen of vertical lens elements.  The camera has 4 lenses
that make four of its 4-perforation-wide (and not quite full-frame high [=22 instead of 24 mml) frames at each
exposure.  The camera is highly adaptable to standard stereography.  Recently, an inferior re-make (NishikaTM) has
been introduced.

*  O.D.: Oculis dexter (right eye).  Often encountered as a technical abbreviation.

*  O.S.: Oculis sinister (left eye).  Often encountered as a technical abbreviation.

*  O.U.: Oculis uterque (each eye; both eyes).  Often encountered as a technical abbreviation.

*  O-Stereoscope: A special transparency stereoscope designed to view the 2x2 inch mounted split frames produced
by a standard 8p planar camera fitted with a stereo attachment (sometimes called a "beam splitter" [q.v.l).  Since the
attachment/lens system transposes the images on their way into the camera, the o-'scope need only "widen" the
viewing path by means of prisms or mirrors.

* OO-Stereoscope: This 'scope is for 2x2 mounted split frame 8p slides similar to those made for use with the
o-'scope, but for the case in which the camera was instead fitted with a miniature pair of lenses with parallel axes.
In such a set-up, the slide in correct viewing orientation will have the left frame to the right, and the right frame to
the left; thus, the frame halves have to be transposed by the oo-'scope.

* Occultation: The obscuring of an object --in whole or in part-- by another object in front of it (i.e. between the
observer and the object).  For example, an eclipse of the sun is an occultation of the sun by the moon.  Occultation
is a major part of the information used by the brain to determine distance: things are assumed to be farther away than
the things which occult them.  One of the reasons that inverse stereo ("pseudostereo") (see) images are so
uncomfortable to view is that the information derived from parallax and the information derived from occultation
are precisely opposed to one another --parallax suggests that an object is close, yet it is occulted by objects which
appear farther away.

* Olden/Tri-Delta (format, attachment): An interesting system that allows a standard 35mm camera to shoot stereo
pairs onto a standard 8 perforation frame. The images are placed top-to-top and must be viewed or projected with
optics similar to those used to make the transparencies. The camera aims skyward in use, so an accessory viewfinder
--looking forward at the scene-- is part of the attachment.  Unlike mirrored attachments ("splitters"), the distortion introduced is not significant.  A 60-degree prism is used in conjunction with mirrors to fit the pair onto the 8p frame. (Compare to: "image splitter", "Elmo", "Savoye".)

 A method of dealing with deviation range (q.v.) in a view when using a non-standard camera lens base in stereography, either in hyperstereography or in close-up work.  (see: "Hyperstereography", "MiRF").  The closest subject matter in a scene should be 30 (or some figure between 15 and 50) times the separation of the camera lenses (or camera stations).  30 times is a value of 160 MiRF.  If the base is one 30th the film-to-subject distance, the apparent distance to the subject in the finished stereograph will be thirty times the normal base (which is roughly the average interpupillary distance, or 65 mm).  Thirty times 65mm is 1.95 meters, or 6.4 feet.  A corollary of this rule is the 3 degree rule for rotational displacement stereography.  Assume that the base-to-distance ratio is 1:30: that means that, if the photographic axes intersect at the given distance, they are converging at an angle of a bit under 2 degrees.  Thus, if one is using a turntable jig to rotate the object being photographed between the two exposures of a sequential stereogram, a rotation of 3 degrees or a bit less will yield a stereogram with similar stereo effect to that of one made by the one-in-thirty rule.  A 3 degree displacement gives stereo separation roughly equivalent to that of a base-to-distance ratio of 19.1, at the "hyperstereo" end of the comfortable viewing range. Staying under 3 degrees of displacement generally avoids shape distortion and images that are uncomfortable to fuse.

* Open stereoscope: See: "Holmes" and "Bates.

* Optical axis: A line through the optical center of a lens and perpendicular to the plane of its diameters.

* Optical center(s) (test for): A ray of light or a line of sight along the optical axis of a lens will pass through its
optical center without undergoing any deflection or displacement. It will strike a screen or target beyond the lens as
if the lens were not there (though a picosecond or so late).  See: "Collimation".

* Optical Transfer Function: A concept developed by Dr. Orville Becklund in analogy to electronic circuits for the mathematical treatment of optical systems.

* Optical Transposition: See "OO Stereoscope" and "Loreo" entries.

* Orthoscopic: When a stereoscopic image can be viewed with its planes of depth in proper sequence (as opposed
to "inverse stereoscopic" (see).

* Orthostereoscopic: Such an image is usually understood to evidence all the requirements incumbent upon a
"tautomorphic image" (see).

* Orthotopic: In the proper or conventional place. Transplant surgeons like this word; a liver transplant is usually
"orthotopic," because the new liver is put in the same place that the old one used to be; a kidney transplant is
"heterotopic," because the new one is usually more convenient to park in the pelvis.  In stereography, the term is
usually employed to indicate that the right image is on the right, and the left image is on the left.  Images designed
for reversing stereoscopes or for cross-eyed fusion would be heterotopic, while images designed for a Holmes 'scope
would be orthotopic.  A confusing wrinkle in the use of this term is in split-frame stereo slides. In the "Hyponar" type
of device (two lenses with parallel axes), the negatives or slide halves may be thought of as orthotopic with respect
to the camera, because the left image is made in the left half of the camera's film aperture and the right image is made
in the right half.  But because the lenses of course invert the image, the images are then heterotopic with respect to
the viewer! When using these terms, it is wise to be careful to be sure that you aren't introducing more confusion than
you're avoiding!

* Over-and-Under: See: "Under-and-Over" Formats.

* Panorama(stereo)gram: When photographic, a stereograph taken with more than two lenses or camera positions;
thus affording more than one viewing position.  Nimslo lenticular prints are an example.

* Pantoscope: See: "Grapho(stereo)scope".

* Parallax: (1) The small disparities in alignments of elements at different distances from the observer in a  scene
when one's viewpoint is shifted from one position to another (chronologic parallax); more relevantly to the topic at
hand, the disparities from one eye to the other.  (2) The differences between any two viewpoints, as between the
viewfinder and the taking lens of a non-SLR.

* Parallax Stereogram: An old autostereogram technique in which a vertical grid (say of wires, separated by their
own diameter) is placed in front of a composite stereogram encoded into corresponding sequentially
left-right-left-right thin vertical strips.  The placement is such that the wires block the right view to the left eye and
vice-versa, allowing only a single fused view to be seen by an observer standing at the correct position.

* PePax: A jargon term for distortions resulting from non-standard perspective and/or parallax.  See discussion
under "Claudet".

* Perforations: Film sprocket holes.  See discussion under "Format".

* Perspective correction: In planar photography, a geometrically adjustable camera (i.e.: "swings and tilts" in a view
camera) or darkroom enlarger is used to "correct" lines in a photograph that appear to converge but are expected to
"look" parallel in the photograph.  If, for classic instance, a simple camera is aimed upwards to take in the top of a
building, the sides of the building will appear to be convergent toward the zenith.  A view camera would allow the
photographer to simply raise the lens and/or tilt both lens and plate holder such that both would be plumb to the
building --resulting in sides that remain parallel on the negative (and print).  Obviously, a wide angle lens (which
must be used with a view camera also) on a small format camera can accomplish the same thing by simply shooting
level and using only that portion of the film where the building is to be found.  The reason that converging building
lines look "wrong" in a planar print is that the print is hung on a vertical wall for display and/or the observer assumes
that the camera was aimed normally at the building.  It doesn't bother the observer that streets and train tracks in the
photograph are seen to converge into the distance, because it's "understood" in our visual psychology that we stand
on the earth and consequently have a vanishing point at the horizon (always assuming that we stare straight ahead
--instead of upwards as the camera did).

However, a stereo view clearly shows us the attitude of the camera because the "window" (see) is (normally) square with and equidistant from the viewpoint of the observer. If the observer can be prevented from seeing the view as two planar images (as with a transparency viewer) before seeing it as a fused view, then upward or downward camera angles cease to create an image that looks "wrong" with respect to "perspective distortion." (Do you buy that?)

* Photogrammetry: A professional discipline which uses aerial photography (and other forms, especially in
intelligence work) for ground measurements and cartographic work (topographic maps).  Stereo pairs, precision
cameras, flight control, and fascinating instrumented viewing/plotting devices are employed.  For illustrative
examples, anaglyphically printed, see Dieter Lorenz's Das Stereobild in Wissenschaft und Technik Deutsche
Forschungs- und Versuchsanstalt für Luft- und Raumfahrt e.V. (2. Auflage), Köln, 1987.  (Available from Reel 3-D
Enterprises (see). (Don't panic; it's bilingually printed in English and German!)

* Photographic axis: A line from the center of a camera's film aperture (i.e.: the "format" or frame on the film)
through the optical center of the taking lens.  In a planar, non-adjustable camera, the photographic axis and the
optical axis are the same. In a 5p 35mm stereo camera, the photographic axes of the two lenses usually converge at
6 to 7 feet from the camera, while the optical axes are parallel.  This is achieved by having the lenses each offset
slightly toward the camera center; that is, each lens is placed a bit medial to the midpoint of the corresponding frame
aperture. This creates a natural "stereo window" (q. v.) at that distance; that is, if the subject is more than seven feet from the
camera, full-frame images will automatically be properly "windowed."  This was a great help to the mass commercial
preparation of stereo slides, in that acceptable "windowing" could be obtained on most views with a standard
mounting protocol --only for close-ups or for correction of horizon or "tilt" error was it necessary to crop in

* Planar (image): Flat, or in a single plane.  Thus, used to describe a two-dimensional or flat image, as opposed to
a stereoscopic image.

* Planograph: See: "inverse" or "Pseudo" stereogram.

* Plasticity: The visual perception that objects have roundness and cross-section (as opposed to "cardboarding").

* Polarization (of light): In nature, certain crystals and angles of reflection preferentially reflect light such that it
is divided into beams that contain light "vibrating" in one plane (vector) or another at 90 degrees rotation to each
other.  Such light can be "detected" by inspecting it with another such crystal or technique.  When the vector passed
by the second crystal is perpendicular to the inspected beam, it of course is seen (through the crystal) to darken.  By
polarizing the light from two projectors in "opposite" (90 degrees from each other) vectors, and by providing the
audience with glasses having similarly polarizing filters, even though both images fall on the same (special metallic)
screen, the eyes see only their respective (left and right) images.  This is conveniently done with filters made of
Polaroid brand film invented by Dr. Edward H. Land in 1932.  Rear projection onto ground glass also works well.

* Print: A vague term, but usually taken to mean a photographic as opposed to a mechanically reproduced image
(in printing inks) in our circles; often used in contradistinction to "transparency" or "slide. See: "Litho".

* Prism: A wedge shaped optical element.  See: "Diopter".

* Prism stereo attachment: See: "Stereo attachment", "image Splitter", and "Elmo".

* Prismatic Lenses: (1) The "semi-lenticular" or "half lenses" of a stereoscope which have prism power by virtue
of being used off axis (see "Diopter" etc.).  (2) See: "Angle lenses.

* Progression: The pattern by which film is advanced and the image frames are sequenced in a stereo camera.

* Projection masks: Are designed such that the centers of the apertures are at a constant distance (as opposed to
--say-- the separation of points at infinity being held constant), thus the projected window always appears to be at
the same distance with respect to the screen. Another approach is to simply let the black surround of the screen be
the window (image runs off the screen sides), but the screen window might not be appropriate to the subject matter.

* Projection-viewer: A table-top device with a rear projection screen like the TDC (division of Bell and Howell)
brand "Project-Or-View.

* Pseudoscope: See: "inverse stereoscopic".

* Pseudostereogram (sometimes "pseudostereoscopic"): (1) See: "inverse stereoscopic".  (2) The same image
presented to each eye, perhaps with a "window" that appears in front of it, but otherwise having no depth (fake

* Pulfrich, C.: Professor Pulfrich discovered visual phenomena and invented optical instruments.  He described the
pseudo (and through cinematic and TV applications, real) stereoscopic effects produced by viewing moving images
with one eye heavily filtered (delayed vision) now frequently used in (sort of) 3-D television broadcasts!

* Puppet theater effect: An apt description of the apparent reduced depth and size when the medium (such as a
lenticular print (Nimslo] or table top rear screen projector) doesn't allow the use of visual infinity.  This is normally
associated with "stretch effect" as well, since the image is further away from the observer than the original image
was from the camera (allowing, of course, for any enlargement factor).

* Q-VU: Folding mask/mounts designed (with Craig) and marketed by Quentin Burke (817 East 8th street, Holtville, California 92250).  They're patterned after the TOA brand Japanese format folders but are made to U.S. standards and allow
the user a choice of adhesives, window separation, styles, colors.  They do for prints what slide mounts do for transparencies.  Various methods of mounting prints into them have resulted in years of controversy.

* Random dot stereogram: See: "Julesz".

* Real image: One that can be caught on a screen (as opposed to a "virtual" image). See: "Actual image.

* Realist (camera): A 35mm stereo camera made by the David White Company and invented by Seton Rochwite.
It uses what became British (3216:1960) and U.S. (ANSI-PH3.11-1953) standard 5 perforation format and Colardeau
progression (see).  Many high-quality devices and services were offered under the Realist trademark.

* Reciprocity failure: Exposure or color error resulting from the use of films beyond the exposure-time range in
which they are designed to perform well. This is occasionally a problem in the use of small apertures and fine grain
films in stereography.  The usual trade-off between shutter speed and lens aperture is known as reciprocity; in
general, if you double the length of time that the shutter is open, an equivalent exposure is obtained by closing the
lens aperture by one 'stop" tie. multiplying the f-ratio by 1.41421 [that's the square root of two, of course, which is
easy to remember because a 14-year-old thinks he's twice as smart as a 21-year-old.]).  Films fail to follow this
trade-off without limit; at an extremely short or extremely long exposure time, there may be color drift or failure to
achieve the expected negative (or slide) density.  For most photographic film, reciprocity is well maintained between
about 1:2000th second and one second; at longer exposure times than one second, a longer exposure than that
indicated by a meter is often required and shifts from neutral color rendering must also be anticipated and
compensated for.  (The problem isn't the time per se, but the low light levels that obtain when such a long exposure
is required. Emulsions have a "threshold" below which response is sluggish or nonexistent.  For special-purpose
photography, there are tricks to overcome this, of which two are worth knowing about: [a] Technical emulsions are
in some cases available in special formulations for longer exposure times --Vericolor PS, for example, is a
Professional emulsion for Short exposure times ....the hard to find PL is a special-purpose film which has
reciprocity in a longer exposure range; [b] It is possible to shift the threshold sensitivity of the film --to
"hypersensitize" it --as for example by brief exposure to extreme cold [this is commonly used for astronomical
photography, and pre-hypersensitized films may be purchased from many telescope dealers].)

* Red Wing Viewer (the): This stereoscope was designed and hand manufactured through the 1980s by Craig, then in cooperation with premier woodworker Luther Askeland (who perfected its design), and finally as a principal project of Luther Askeland with Aura Optics of Minnesota supplying finished lens pairs and Craig supplying finished brass parts. It was designed to be compatible with mainstream design standards of traditional stereoscopes and viewcards (following a survey of Keystone, Underwood, and other cards and stereoscopes). It appears to be the only standard print-pair stereoscope ever sold with published specifications --and for making new viewcards to use in it. See also the "Holmes-Bates Stereoscope".

* Reduced Base:  See the "Hypostereo" entry.

* Reel 3-D Enterprises, Inc.: A U.S. catalogue source of general stereographica.

* Relief: The appearance or fact of depth such as in carvings or stereography.

* Retinal rivalry: When a stereo pair are dissimilar, particularly with respect to density or positive/negative
reversals, the eyes only allow the images to be seen one at a time in alternation.  Vision defects cause this too
(differential color blindness, for instance).

* Reverse: The back side of a stereocard (or of any printed item). This term is less likely to provoke low humor than
is the term, "backside."  The reverse of a card often bears an extended legend, or information concerning other
offerings of the maker.  ("Verso" may be the preferred term.)

* Reverse(d) window: A term used to describe a stereo window (see) in which the margin conventions are reversed
...that is, the nearest object has a wider left margin in the left frame and a wider right margin in the right frame.
Actually, the stereo window is not truly reversed; rather, it is positioned more distant from the observer than is the
nearest object.  If that nearest object touches or crosses the frame margin, this may give rise to disconcerting effects
that make the view considerably less comfortable to fuse.  The margin conventions are more fully described and
charmingly illustrated in the entry, "Stereo window.

* Rising front: A camera lens panel which can be raised while the optical axis remains level and the film plane
plumb.  See: "Perspective correction.

* Rotation (or "twist"): A difference between stereo pairs in which the horizons (whether or not present) are not
level to each other.  This is more disturbing than straight vertical discrepancies.

* Rotational displacement stereography: A technique for sequential stereography (see) in which the displacement
between the two planar images is angular rather than linear.  Either the camera or the subject may move.  In the
former case, the camera may be mounted on an arm like the attached stool of some barber's chairs, and thus swing
around the subject in an are.  In the latter case, the object itself is rotated, often on a turntable stage, while the camera
remains stationary. In either case, the lighting must be very diffuse or the lights must remain in a constant orientation
with respect to the subject; otherwise, the shadows will have noticeable differences between the two frames, and
strange effects may result.  See: "Hammerschmidt jig" and "SLAWE effect" and "Umbus perpendicularis.

* Savoye format: A wide stereo format produced by a special attachment on a planar camera (still or cine).  The
images are over and under on a standard frame, oriented bottom-to-bottom. C.f. "Elmo", "Olden/Tri-Delta", "image

* Scopeability: A jargon term used in reference to a view's over-all ease of being viewed. Standard separation of
homologous points, suitable deviation, absence of rotation, a well placed window, balanced printing, accurate image
alignment/masking/trimming --- all of these contribute to a good view.  This is sometimes spelled scopability, but
to describe the difference as a point of controversy would be overstatement.

* Separation: See: "Base" and "Homologous distance.

* Septum: (1) The partition used in a stereo camera to separate the two lens to film paths.  (2) Any partition or
design element that effectively separates the lines of sight of the eyes such that only their respective left and right
images are seen.  (3) The gap between the stereo pair of a print view. (4) That which separates your left nostril from
your right nostril.

* Sequential stereograph: A stereograph in which the two (or more) planar component images are not taken at the
same time.  Rather, the camera is moved between the (usually) two exposures, or the subject is moved between the
two exposures, or the spatial relations among the subjects (as in a diorama) are changed between the exposures.
Obviously, when still cameras are used, this technique is suitable only for stationary objects --we specifically do not
recommend it for small children or Springer Spaniels.  It can be used for moving objects, though, when the
non-simultaneous images are alternating frames of a cinematic (movie) or video image.  Often a motorized camera
is used to record sequential images of passing scenery as "dolly shots" on the ground or from an aeroplane.  Adjacent
frames on the film can be used as stereo pairs (with slight discrepancies due to motions within the scene) if the
distance between snaps is appropriate to the near point of the scene.  This technique can also be used in "Pulfrich
effect" (see) stereo cinematography.  See: "Slide bar, "Shift technique", "Rotational displacement stereography",
"Hammerschmidt jig".  Don't bother to see "Shift bar", as that entry will only refer you to "Slide bar".

* Shift bar: See:"Slide bar".

* Shift technique: A technique for taking sequential stereographs without special equipment. If one is using an
ordinary planar camera such as a 35 mm SLR or "point-and-shoot," the first image is taken with the body's weight
on/over one foot.  The second photograph is the taken after simply shifting weight to the other foot.  The amount of
lateral displacement caused by such a weight shift is generally within the range that will give a satisfactory
stereograph.  This is sometimes called the "astronaut shuffle," because it was occasionally used by NASA astronauts
to make stereographs on space missions. Those of us who learned it from our stereographer fathers long before there
were such things as astronauts eschew this term as an anachronism.

* SILO effect (an Acronym for Smaller In, Larger Out, brought to our attention by Dr. Fred Weitz [SSAB#848],
an optometrist stereographer): Minification by exaggerated lateral parallax. In views made in the "hyperstereo" range
(see), the object depicted often appears smaller than it really should.  This is sometimes called by stereographers'
jargon terms such as "Lilliputianism"; the optical effect of reduced apparent size is technically known as
"minification" --- the direct opposite of "magnification."  (It is sometimes also called "miniaturization"; this term
more properly refers to the actual rather than the apparent reduction in size of something.)  The most familiar
examples of minification are the effect of looking backwards through an ordinary pair of binoculars, and the size shift
on viewing through corrective lenses for nearsightedness.  The minification seen in hyperstereo is particularly
interesting, because it does not result from a change in the image size; rather, it results from excess parallax, from
the wide spacing between the two taking lenses.  This yields a discrepancy between two sets of input to the brain's
cortex.  If the image is a familiar one, there are similar images in the brain's library of remembered images, and size
and distance estimates will be made from simply comparing the planar image to those remembered ones.  The degree
of difference between the two planar images of the stereograph, then, is such that the image looks much closer --that
is, there is a greater degree of apparent convergence than would fit with the distance estimate made from the planar
view alone.  To anthropomorphize a bit (if indeed one may call it anthropomorphization to liken the human brain
to a human), the brain may then be thought of as trying to reconcile these two discrepant distance estimates.  One
resolution is to conclude that the eyes are suddenly much farther apart (and the object is as far away and as big as
you'd guess from its planar appearance); another is to conclude that the object is really smaller than would be guessed
from the planar view (and really is as close as the stereo effect would suggest).  The former resolution fits no
previous experience or established anatomical connections, while the latter will have experiential precedent
(everybody's seen doll houses, for example).  The brain usually chooses the latter, or makes a compromise, and
perceives the depicted object as smaller than it really is. If the object pictured is not a familiar one, the brain just can't
decide how big it is.  (The acronym "SILO effect" refers to the handling of the image at the cortex.)  Minification
through parallax effect is also termed "convergence micropsia.

* SLAWE effect: Acronym for "Shadows Look Awfully Weird, Eh?  A Manitoban variation on Umbus
Perpendicularis Shiftus ---OOPS (see).

* Slide bar: A device for taking sequential stereo pairs for still life stereography. A planar camera is
shiftedhorizontally between exposures.  The optical axes for both exposures should be parallel, but are often "toed-in"
to conveniently create a "window."  Such toe-in will be acceptable if not too extreme; one must use great caution,
however, in that it may produce enough keystoning (see) to be a problem, and may increase the background
discordance. Commercial slide bars are readily available and of excellent quality; however, because they are most
often manufactured and sold for other purposes, your friendly neighborhood photo dealer may stock quite an
assortment without even knowing it.  Some of the best are actually marketed as fine-positioning rails for copystands;
but they are perfectly happy to sit on tripods instead of copystands, and they provide a calibrated rack-and-pinion
track with a locking screw. An example of a good quality device for under $50 (1990 price) is the "Quadrail" positioning bar sold by Spiratone, a mail-order photo supplier in Flushing, New York.

* SMPTE: The Society of Motion Picture and Television Engineers determines and lists standards for equipment,
formats, and techniques of imaging systems.

* Snap 3D Camera: {Entry pending --classified information as of March, 2004]

* Social Animal ("Man is a ---"): Baruch Benedict Spinoza, 1632 - 1677, persecuted free thinking philosopher, heretic, and lens grinder who managed to get himself excommunicated as a Jew and stated: "the most tyranical governments are those which make crimes of opinions, for everyone has an inalienable right to his thoughts".

* Social Stereoscope (The ___): Dissertation by Marilyn Faye Morton, Emory University, 1998. The Social Stereoscope "examines the field of stereography --the three dimensional variant of the photographic medium --that set a new standard of pictorial truth for a virtually naive consumer base in the mid-nineteenth century."

* Space control: A technique of trick photography in which multiple exposures or printings insinuate one image into
another such that they appear to share the same space.

* Space image: An image that appears to be solid with scene elements at varying distances from the observer.  A
space image, whether still or cinematic, is "static" in that only two fixed perspectives and one fixed set of parallax
values for the scene elements are available, as opposed to a scene in life or the reconstructed light wavefront from
it offered by a holographic image.  Both types of space image are very distinct from the simple "actual image" (see)
or "real image" which can be projected onto a flat screen and/or treated as such.

Note: We know of no term for a holographic or life image, except stated as such.  The term "Dynamic Space image" (again, either still or cinematic) seems to be a possibility.  An integrated multi-station stereo view such as an XogramTM or NimsloTM lenticular print occupies a middle ground in that if offers a series of fixed perspectives, simulating a "life" or "dynamic space" image.

* Spectacles: In stereoscopy: glasses worn for the purpose of decoding a composite stereogram, projected or directly

* Spinoza --see: "Social Animal".

* Split frame format: Usually, a stereo pair recorded on a single frame of a planar camera's film by use of a stereo
attachment.  May be side-by-side or over-and-under.

* Split stereogram: Not really a complete stereogram in that the subject matter of each of the pair is supplemental
to the other.  Usually done as a stunt.

* Squeeze: (1) The opposite effect of "stretch." The perceived flattening effect caused by walking towards a
projected stereo composite image or viewing (magnifying) the image (side-by-side) pair with ever shorter focus
ocular lenses.  This occurs when the use of long telephoto lenses are attempted for stereography.  You then have to
use equally long viewing lenses to make the view "'scope" right (thus: defeating your purpose).  See: "Stereo
telephotography."  (2) Methanol, especially that mechanically extracted from jellied methanol (e.g. SternoTM).  The
folk etymology is probably accurate, here; the name derives from the practice of forcing the jellied methanol through
a nylon stocking to separate the methanol from the semi-solid matrix.

* Standards: See: "ASA," "SMPTE," and "ANSI."

* Stereo: From the Greek word "stereos," meaning solid.  Thus, a term or prefix referring to processes which add
depth.  Stereophonic sound is sound which allows depth to be perceived, as Stereography is photography in which
depth may be perceived.

* Stereo acuity: The ability to distinguish different planes of depth, which depends on the smallest angular
differences of parallax that can be resolved binocularly. Under laboratory conditions (and --probably-- with visually
large targets), claims have been made for the detection of parallax differences as slight as 3 seconds of arc!  For
practical stereography, a value of 1 minute of are (the same as average [20/20 vision] detail resolution) might be best
assumed.  This value determines the maximum distance of "stereo infinity" (which see).

* Stereo attachment: A prism or mirror device for taking stereo photographs with a planar camera.  The common
types split the frame into two side-by-side images.  Another splits the frame horizontally (see: "Savoye").  See also:
"Twin lens attachment".  See discussion and illustration under: "image splitter."

* Stereo Base: See "Base".

* Stereo diplopia: See: "Dynamic stereo diplopia".

* Stereo Guild: An international association of stereographers that circulated 35mm stereo slides among the
members.  See: "Herbert McKay".

* Stereo infinity: The farthest distance at which stereo effects may be seen. If it is assumed that the smallest resolvable angular difference in parallax between the eyes is 1 minute of are (.0003 radian), then one should not be able to distinguish any depth beyond scene elements that are about 700 feet distant (at least not without moving one's head from side to side to increase the parallax).  The actual average limit (threshold) of resolvable parallax is now considered to be about 6 seconds of are for a stereo infinity of 7000 feet(!) but that's hard to capture in a photographic stereo pair.

* Stereo macrography: Stereo photography in the "macro" range. As in planar photography, this term is generally
used to describe images in the range wherein the film image is approximately life-sized.  In other words, stereo
macrography is the stereography of subjects such that the finished view presents a size magnification of =1x (as
compared to what would be seen in life of the subject at 10 inches [25.4 cm] distance) to 10x.  See: "Stereo

* Stereo magnification: When a stereo camera with lenses of the approximate separation of human eyes is used to
make a stereograph, when the stereograph is viewed at film image size through stereoscope lenses of the same focal
length as the camera's, then the stereo magnification is considered to be unity (one x).  If the camera lens base is
doubled, the stereo magnification is then 2x.  Because of the need to keep the "deviation range" of a view within
limits, stereographs that contain subject matter both distant and nearer than 5 feet (or so) are either avoided or taken
with reduced lens separation, which is stereo demagnification".

**Don't confuse stereo demagnification ("hypostereo") with its main effect: subject magnification by decreased
parallax.  Stereo magnification ("hyperstereo") causes subject "minification" by means of increased parallax. These parallax effects are considered separately from any actual planer subject magnification in the view.

* Stereo micrography: Stereo macrography of a more extreme degree. The prefix micro- is often applied in both
stereo and planar photography to images with magnification that is in the range of a microscope (such as a dissecting
'scope) rather than being just close-ups in which the film-plane image is as big as the object being photographed.
Customarily, the prefix macro- is applied up to about 10 magnification, and micro- is applied for magnifications
greater than 1Ox.  Ideally, stereo demagnification tracks size magnification at about 7 to 1 for "scopeability."  A size
magnification of 10x (i.e.: camera distance is 1 inch to subject) would use an equivalent camera base reduction of
1/70th the normal 65mm to 70mm.

* Stereo projector: A device (which might be an unadapted planar projector in the case of anaglyphic slides) for
projecting stereograms upon a screen.

* Stereo radiogram (or radiograph): An X-ray stereogram Typically, these are made to determine whether a "coin
lesion" (a small, round, shadow suspicious for tumor) is within the substance of the lung or not.  A standard chest
X-ray is made, then the patient is rotated a few degrees and the process is repeated.  Since the advent of computerized
axial tomography ("CAT scans") (which produces X-ray or magnetic  resonance images looking like salami slices)
the stereo technique has seen far less used; it is still sometimes used in rural communities, where access to CAT may
be limited.  A stereoradiogram may also be called a Stereorröntgenogram or a Stereoskiagram (Roentgen [or:
Röntgen] was of course the discoverer of X-rays, and skia is old Greek for shadow).

(It was Dale's painful experience with a broken collar bone which delivered him to the mercies of a by-the-book X-ray Technician --who murderously (of the X-ray plate pair) rotated poor Dale to accomplish an old fashioned stereoradiogram.  Much more information could be viewed in such pairs if technicians used displacement of the X-ray cavity/source instead.
Anyone who's worked with the old and delightful technique of rear-projected shadow anaglyphy will immediately appreciate my opinion.  See the new ['97] entry "Keystoning Distortion" for more discussion. --CFD)

* Stereo telephotography: The theory and making of stereographs with longer than normal camera lenses, which
isn't simply the inverse of stereomacrography.  It is better thought of as the opposite of wide angle (i.e.: short focal
length) stereography.  Wide/short camera lenses result in views that --when viewed in a normal 'scope, suffer from
"stretch," due to the disparity between taking and viewing focal lengths.  The opposite occurs ("flattening", or
"squeeze" [see) when taking lenses are much longer than the viewing lenses.  Resorting to a wide base (say, two
synchronized SLR cameras overlooking a cityscape from a cliff) to make up for the "squeeze" introduces apparent
geometric distortions in the subjects (ie: the back of a passenger bus seems suitably further away, but it's just as big
as the front [!]; therefore [saith the perplexed brain], the cross section of the bus must enlarge toward the rear end.).  This might properly be called "frustum effect" (see).

* Stereo telescope: Invented by Hermann von Helmholtz, this is a binocular optical device that magnifies depth
(stereo) instead of (or, as well as) size.  Used for gunnery and other ranging equipment; if one or more of the mirrors
or prisms can be rotated through a measured angle, the angle of convergence for fusion can readily be determined
and the distance to the object inferred with reasonable accuracy.  Simply put, this is an overgrown version of a
camera rangefinder. Also called (by the inventor): a "telestereoscope."  See "Claudet" and "Minification."


* Stereo typogram: A stereogram produced by shifting otherwise identical type between a left and right pair.

* Stereo views: Any stereogram, but often used more specifically to refer to the standard American format
stereocard, 3.5 x 7 inches in size.

* Stereo window (of a view): A basically simple concept that for some reason is not intuitively obvious, and causes no end of confusion to newcomers to stereography.  If one views a stereograph, it is generally most comfortable if it is mounted in such a way that one appears to be viewing the three-dimensional image as though through a window. This mythical window is the "stereo window."  If one does not mount stereographs in this manner, the edges often have a distracting "choppy" or "floating" appearance to them.  The way it works is outlined in the following figures, in what we hope to be an informative manner:

When viewing through a window, the right eye sees a bit more to the left, and the left eye sees a bit more to the right.  Mounting
stereographs correspondingly creates an apparent "window," through which one views the subject.  [image]

The most comfortably-viewed stereographs are ones in which
all objects appear to be on the far side of the "window," with the occasional exception of an object which may appear to pierce the plane of the window other than at the edges.

As you can perhaps appreciate from the above, an object on the far side of the "window" will appear to be more to the right in the right-hand image (that is, have a wider margin on its left side) and more to the left in the left-hand image (have a wider right-hand margin).  Just the opposite is true in an object which is closer to the observer than the "window":
And finally, if somewhat obviously, an object which is in the plane of the "window" will be identically positioned in both frames:

Ordinary practice would be to have all images in the view appear as though they are beyond the plane of the
"window." It may occasionally be effective to have an object poke through the plane of the "window"; that's not
distracting if it is something which physically could do so in a real window.  But if it's not "physiologic," it can be
very distracting.  For example, a person should not normally appear to have his head cut off by the frame of the
"window," such that it seems to float in disembodied splendor in the middle of your stereoscope!

A special case worth mentioning is the use of windows with arched tops. Because the arches are in part vertical, they
give distance information. Therefore, if one uses the upper edge to align the homologous points in a print, there is
a great danger of error; homologous points should be the same distance below the top edge (of a curved top) only
if the object is meant to be in the plane of the "window."  This may be seen in the illustration below. The
caneweave-patterned blob is in the plane of the "window," and is identically positioned in each frame.  The speckled
blob is behind the "window," and is slightly further down from the top edge in the right-hand "chip."  But it's the
same distance up from the bottom of the image in each "chip."  It is best for arched tops to make all measurements
from the bottom, and with great care.

* Stereo window(camera): A stereo camera may be constructed to be "self-windowing" without keystoning by
having its photographic (camera) axes converge, even while its optical axes are parallel.  This is achieved by having
the lenses offset from the center of the film aperture.  See illustration under "Photographic axis".

* Stereo window (viewer): In certain stereoscopes such as the Keystone Telebinocular, the "window" is a physical
rather than a virtual thing: A mask determines the stereo window and it is sometimes referred to as such.

* Stereogram: The artificial 3 dimensional image as a whole. It may consist of a side-by-side pair, a coded
composite, or a sequence that is coded by persistence of vision.

* Stereogrammetry: See:"Photogrammetry".

* Stereograph(y): (1) A photographic stereogram and the making of such. (2) (now obsolete): the art and practice
of solid drawing.  See "Tamari, V".

* Stereographoscope: A heavy table-mounted viewer that carries a large monocular lens above the two regular
stereoscope lenses.  The tongue (or stage track) slopes downward and carries a sliding stage that can hold large planar
photographs as well as stereographs.  Sometimes called a pantoscope.

* Stereophoroscope: A calibrated stereoscope for the viewing of calibrated stereo images, used for the measurement
of stereopsis, exophoria, etc.; e.g. the Ameson Stereopsimeter.

* Stereopsis: The physiological and mental phenomenon of converting binocular vision parallax differences into
the sensation and awareness of depth; a "space image" in the cyclopean center or mind's eye.  See: "Dynamic stereo

* Stereopticon: A troublesome word, which in common parlance has come to denote --inaccurately-- a stereoscope.
The Oxford English Dictionary cites Knight's Dictionary of Mechanics as the earliest appearance its researchers
found in print (1875); in that instance, it referred to a dissolving twin-image "magic lantern,' which could be used
to convey information about depth by the blended sequential presentation of a series of planar views of a subject.
Such presentations, while perhaps dramatic to the audience of a century and more ago, were not stereographic.  The
word was also applied to less fancy, single "magic lantern" transparency projectors, such as those used to project song
slides in the nickelodeon days.  Stereopticon is said also to have been a commercial name for a traditional
non-reflecting opaque projector which allowed the projection of a printed image (say a photograph or a post card
picture) onto a screen by means of a large lens system and intense light (and heat!).  The word Stereopticon has
nothing to do with stereography except for its all-too-common misapplication to various stereoscopic devices.
Unfortunately... two of those misapplications have been by manufacturers of stereoscopes!  The earliest (that we're
aware of) was Rawson's "Stereopticon" of 1867 (see: Stereo World, March/April of 1980).  The latest is the current
"Stereopticon 707" by the Taylor-Merchant Corporation (a cardboard folding viewing device).  And perhaps even
more unfortunately...the usually-scholarly Smithsonian Institution has (May, 1990) Holmes-type stereoscopes on
display, bearing labels identifying them as Stereopticons!

* Stereoscope: (Usually) a lensed, prismed, or mirrored device for fusing and viewing stereo pairs of images. See "Lenticular Stereoscope".

* Stereoscopic Society: An international association of branches and individuals dedicated to the practice and
advancement of stereoscopy.  The noble American Branch is in association with the National Stereoscopic
Association; in 1990, recognizing that formal ties with the parent British Society no longer existed, the American
Branch officially changed its name to the Stereoscopic Society of America.

* Stereoscopic: Means "solid looking." May refer to any experience or device that's associated with binocular depth

* Stereoscopic base: See "Base" entry.

* Stereoscopic projection: Traditionally refers to projecting a stereo pair onto a large screen such that many can
see the images.  Various means have been used to "code" the images at the projector(s), then decode the pair again
--respectively to the left and right eyes of onlookers.  See "Eclipse", "Polarization", and "Anaglyph" entries.
Projection might also refer to virtual optical, direct retinal scanning, reflex display systems, and holographic

* Stereoscopic Reflector: See "Beam splitter" entry.

* Stereoscopic synthesis: (1) Same as "stereopsis" (q.v.).  (2) Refers to research evidence (using random dot
stereograms) that stereopsis is somewhat of an independent "6th sense" (after balance, touch, taste, etc.).  There may
be a region of the brain dedicated to processing and analyzing the parallax differences between the perspectives of
one's left and right eyed vision.

* Stereosynthesis: At this late date (8/6/06), Craig (co-author of Glossary) has finally learned (by happening across it during a Google search) of an earlier coinage plus trademark usage of the term: "StereoSynthesis" by David M. Geshwind. Geshwind is the fellow who figured out how to colorize early black & white movies (1986 patent process) using computer assisted editing techniques --which are more like human-assisted computer techniques. He realized that this same system could be adapted to track and assign parallax information to image objects, demonstrating and patenting this process in 1990.

As president of 3DMG, Geshwind has recently licensed the use of his process to IMax for the conversion of segments of "Superman Returns" into 3D.

Craig doing business as "StereoType" in Florence, Oregon, came up with this same term as a name for his conversion of 2D commercial art to "in the round" photo-realistic stereo pairs. He planned out the conversion with hand drawings, trigonometry, and homemade charts, then executed it by using the excellent general purpose graphics program "Picture Publisher-3.1", which was developed by Micrografx for PC computers.

* Stop: (1) Usually refers to the "f-stop" of a camera lens, which is the numerical value of its effective focal length
divided by the adjusted diameter of its lens aperture.  Usually, these numbers are expressed in even multiples of the
square root of 2 (1.41421): f:1.4, f:2, f:2.8, f:4, f:5.6, etc. It is denoted (e.g.) f:5.6 because the effective size of the
opening is the ratio between f (the nominal focal length) and the f-stop number (5.6 in this example).  The "effective"
focal length is generally the distance from the nodal point of the lens to the filmplane; it's equal to the lens's nominal
focal length when it is focused at infinity.  At extremely close distances ("macro" range), the difference between
nominal focal length and effective focal length may become great enough to require correcting the exposure --that
is, the lens is far enough from the film that the "distance" part of the ratio cannot be assumed to be close enough to the focal length to make no difference.  The "adjusted" diameter is a term that is used because --depending on the design of the lens and the precise location of the iris diaphragm ---the actual diameter of the opening in the iris may not give accurate exposure information. It may behave as an opening of a slightly different size.

(2) An increment of exposure that halves or doubles the amount of light reaching the film.  For example, a one-stop overexposure is made by opening the lens aperture by one step, or by doubling the time that the shutter is open. The light passed is doubled by increasing the diameter of the lens aperture by the square root of 2.

(3) Any aperture which controls light or line of sight.

* Stretch: results from viewing an image pair from an effective distance greater than that of the camera's distance
from lens to film.  This occurs when the focal length of a viewer's lenses is significantly longer than the focal length
of the camera in the case of transparencies.  For prints, the viewer focal length can increase over that of the camera's
in direct proportion to the enlargement of the print (cropping has no effect).  It is common for a stereoscopic system
(ViewMaster, Realist, etc.) to incorporate a stretch factor of 1.4 or so, as well as some hyperstereo effect (see).

Note: This presents a problem in using the much sought after wide angle (i.e.: short focal length) lenses for stereo
photography.  See also "Stereo telephotography" for the opposite problem of resultant "squeeze.

* Supplementary lens(es): See: "Accessory lenses.

* Table viewer: (1) See: "Projection viewer".  (2) See: "Graphoscope".

* Tamari (Vladimer): is a Palestinian artist and inventor (now living and working in Japan, apparently) who feels
that the longstanding practice of "flattening" our real world onto surfaces for its representation has made us culturally
"space blind": unable to conceptualize three-dimensional space realistically.  He has invented (1963)† a mechanical
instrument for direct stereoscopic creative drawing in the round.  It consists of a held stylus ("space pen") that
couples to two pens moving on two sketch pads which are viewed stereographically by the artist.  Downward motion
of the stylus causes the pencils to separate slightly, thus creating the wider parallax required for an illusion of depth.
The pencils otherwise follow the freehand motion of the stylus in the X & Y coördinates. Tamari points out to us that this isn't simply a method of creating 3-D drawings, but a new method of drawing per se.  He has developed accessories that include: a spherical compass, a universally orientable plane, an axonometric perspective 3-D template system, and an optical method for
visual projection of 3-D drawings over real space (to "see" one's drawings superimposed in actual visual space
superimposed on 1:1 scale with objects seen at near or vast distances).  The architect, for example, can sketch cos
(q.v.) building upon the vacant building site. Tamari's drawings are, of course, breathtakingly beautiful to befuse.
One can imagine a fully perfected computer graphics workstation version of Tamari's invention: --which allows the
artist to (say) command a cartoon character to turn around in order to complete its other side and then enter the
complete beast for further reference and manipulation/progressions. An X-Y-Z 3-D electronic brush in the right
hand, a joystick in the left that controls a spectrum of color left & right while setting shade/tint to & fro. An index
finger pressure trigger on the right (held-like-a-pencil) could control "tweening", etc. features from on-screen menus.
(CFD -March, 1990)

†Japanese Patent #762196,50.3.24. Vladimer Tamari, 3DD Co. Ltd., 1-36-16-101 Sakurahimmachi Setagaya, Tokyo,
Japan.  Tel. 704-1269.

* Tautomorphic image: A stereoscopic view that presents the original scene to the observer exactly as co would
have perceived it in life; with the same apparent scale, positions of scene elements, and a stereo magnification of one
for all subject matter in the view. Many familiar stereoscopic systems use "stretch" and "hyper" factors of 1.4 or
more.  Herbert McKay and J. G. Ferwerda consider such departures from ortho (say: between 0.7 and 1.4 [there's
that square root of 2 again, cropping up everywhere]) to be unnoticeable.  (The credibility of those who complain
about lack of depth in 55.5-mm-base Nimslo pairs is challenged here.)

* Telebinocular: Keystone's brand name for a stereoscope with built-in window masking, producing results similar
to that of viewing a stereo slide (in that your world view contains only the view, surrounded by blackness).  The
'scope only works well with views made to Keystone's standards of format (adjacent print pairs, 3 inches wide, and
floating separation of homologous points at infinity [anything from 3 to 3-3/8 inches] to keep the print format
constant between normal and close-up views).  The deluxe versions came with a hazardous electric lamp that worked
poorly with curved views.

* Telestereoscope: See "Stereotelescope".

* Three-degree rule: When using rotational displacement between views, a 2° shift is roughly equivalent to a
base-to-distance ratio of 30 (actually 1.909"), and a 3° shift is roughly equivalent to a ratio of 20 (actually 2.862").
Thus 3° is at the "hyperstereo" end of the routinely comfortable viewing range, and exceeding 3° displacement may
introduce noticeable shape distortion or may result in an image which is uncomfortable to fuse.  It is therefore a
useful rule of thumb to work at two to three degrees angular displacement when using turntable techniques.  See:
"Hammerschmidt Jig," "One-in-thirty rule, "Rotational displacement stereography."

* Three-dimensional or "3-D": The pitch man's way to say "stereoscopic".  Derived from René Descartes' system
of coördinates, which assigns two dimensions to a plane (usually denoted x and y), and three dimensions (x, y, and
z) to a solid space.

* Tilt: (1) Non-horizontal orientation of the horizon in a stereo view. A stereographic view in which the horizon
(whether or not present) is not level to the format is thus said to be tilted.  (2) The rocking of the lensboard of a
camera (or enlarger) about a left<--->right axis, used for example to correct keystoning distortion (q.v.) in
photographing buildings.

* Tilting stage: Used in microscopy to produce a sequential stereo pair.  Sometimes a "rocker" or "teeter-totter"
setup is used in which a pin is placed laterally under the slide at the optical axis, the diameter of which is no more
than about 1/50th the slide's length --producing about 2.3 degrees rotation of the (top illuminated) subject.

* Tissue: A translucent print stereograph, often tinted and of French origin.

* Toe-in: The creation of a stereo window when using planar cameras by the expedient of aiming their optical axes
to converge at the desired window distance.  See the "keystoning" discussion.

* Transposition: Reversal of the two images of a stereo pair. Because lenses produce inverted images, stereo
cameras produce a stereo pair that are reversed, left for right, if viewed in otherwise-proper orientation on the film.
If the pair is on a single piece of film, the images must be transposed by (1) cutting them apart and swapping them, (2) using a transposing viewer, (3) using crossed free vision, (4) using a LoreoTM or ArgusTM stereo camera.  (Sorry, a mirror won't work.)

* Tri-Delta: See: "Olden/Tri-Delta".

* Tru-Vue: The Tru-Vue company preceded, parallelled, and then was bought-out by ViewMaster.  It was the first
U.S. company to distribute views on 35mm film (strips) and its titles included many fine travelogues.
Non-transposing viewers were marketed to use with the film strips.

* Turn-table Stereography: See discussions under "Base", "Toe-in", and "Keystoning"..

* Twin lens attachment: A pair of small lenses on the same lens "board" that fit a planar camera with
interchangeable lenses such as a 35mm SLR. See: "Split frame" and "Format."

* Umbus Perpindicularis Shiftus effect (or "UPS effect" and popularly called "OOPS!"): Thanks to NSA member
Rob (tongue-in-cheek) Oechsle of Okinawa, we now have a proper definition of this vexing phenomenon: "Stereo
photographs produced by the shifting of a single camera with an ATTACHED light strobe will produce shadows
perpendicular to the axis of depth, emanating in a flat plane from each solid object or point causing the shadow." Or
in other words: "This is caused by the constant lens/strobe/object angle that is maintained without regard to the
changing position of the camera.  The shadows will always be in flat sideways protrusion from --and in the plane
of-- the objects they are cast from.

* Under-and-Over formats: These are systems in which the left and right pair are presented above and below each
other, either as formatted on a film frame (see stereo attachments), matted together as a pair of prints, or scanned as
a top and bottom separated pair on a television screen (to be viewed with prismatic glasses, such as the "KMQ" brand
viewers).  Generally, a mirrored or prism viewing device is used to enable the observer to fuse the pair.  These
systems lend themselves to images with wide "aspect ratios" (image width can far exceed height) whereas
side-by-side systems lend themselves to tall aspect ratios. Such a format is sometimes used in the gallery display of
stereographs, as it may be used for views of almost any size --one merely views larger pairs from a greater distance.

* Verso: See "Reverse".

* Vectograph: A polarization coded stereoscopic transparency that is viewed "directly" with polarized glasses. An
invention from Dr. Land's laboratories.

* Viewer: (1) A vague term that, among stereoscopists, refers to any device that either decodes (glasses) or allows
fusion (stereoscope) of stereograms. (2) The person viewing a stereograph; for clarity, it is probably better to call
the person the observer rather than the viewer.

* ViewMaster(TM): A system of stereo photography, characterized by small transparency pairs mounted in a flat,
circular reel.  Originally a product of the Sawyer Company, it remains the only mass marketed system (at this
writing) for viewing stereograms that penetrates the U.S. market.  Its familiar reels holding 7 pairs of little
transparencies enjoy over 33% market survey product recognition.  The product line in the United States once
included a very high quality ("Personal") camera and many beautifully photographed reels depicting travel, natural
wonders, science and engineering themes, traditional children's stories, and significant events.  Good reels are still
obtainable from importers (and collectors/dealers), but the current reel production is mostly cartoon pap.  Sources
as of early 1993: Charley van Pelt and Associates, 1424 East Mountain Street, Glendale, California 91207.
Worldwide Slides, 7427 Washburn Avenue South, Minneapolis, Minnesota 55423.  See also ads and listings by NSA
collectors and dealers.

* Vignetting: Darkening or cutting off of an image as one gets farther from the center; this may be done deliberately
to create a mood, or it may be an image flaw. This is only peculiar to stereography in that certain brands and models
of stereo cameras are known to shade off the corners of their film format at small apertures (Realist and Revere
Cameras with 1:3.5 lenses).

* Virtual image: See discussion under "Actual image".

* Waack, Fritz G.: Author of Stereo Photography (translated into English from the original German and published
in 1985; English version edited by Susan Pinsky and David Starkman of Reel 3-D Enterprises, who also distribute

* Waterhouse stops: Lens apertures which are not variable, usually consisting of simple holes in a metal plate,
which is either placed before the lens or slid between its elements.  Many inexpensive cameras use Waterhouse stops
to control exposure; the film speed selector inserts such stops either into the light path to the photosensor, or into the
photographic light path.  When John Waterhouse introduced these in 1858, he probably didn't envision their
application to anaglyphic stereography (a pretty safe bet).  You can apply pairs of small (say: f/16) apertures to the
front of a modern SLR lens (50+mm and f/1.4, say), cover them with red and blue-green filters and do room-scale
or close-up anaglyph stereography using standard films and processing.  Make the blue aperture half again as large
as the red.

* Whack: The brand (or imprint) of the (claimed) first U.S. anaglyphic cartoon comic book.  The editor said: "Let's
give it a 'whack'!"  (Not to be confused with "Waack, Fritz G." --or with anything else, for that matter).

* Wheatstone, Charles: The inventor (1838) of the stereoscope that bears his name (and the word "stereoscope";
and the Wheatstone bridge, useful for measuring electrical capacitance and/or resistance).  The Wheatstone 'scope
fuses a stereo pair of images with the aid of mirrors or reflecting prisms.  This was the first stereoscope (if you
discount F. A. Elliot's 1837 eye-scrootcher) and was invented before photography.  Amazingly (and several years
of cybernated ancient literature searches confirm): Wheatstone was the first person to appreciate the nature and
publish the principles of stereo vision and stereoscopy.

* Window: See: "Stereo window" and "Mask".

* Witness notches: The bottom edges of the film plane apertures in stereo cameras usually bear notches that identify
left from right frames and what brand and model of camera was used.  The Nimslo camera --oddly-- has instead a
witness "tooth" in one of its versions (invert the camera when you file it off --to keep filings from getting into the

* Wodniw: A slang term for "reversed window, (see) the circumstance in which the "stereo window" (see) is located
to the far side of the nearest object, with distracting consequences.

* XographyTM: A proprietary name given to a lenticular autostereo print view system that works very much like
NimsloTM prints.

This glossary first appeared in the Viewsletter / of the Stereoscopic Society and was without any copyright from the
original version's author: Craig.  This very much improved edition owes everything to Dale for its motivation and illustrations plus a large debt to his contributions of new items and rewriting
of old ones for clarity and form.  It has also benefited greatly from the recent (and excellent!) book: The World of
3-D by Jacobus G. Ferwerda.  My original knowledge of stereoscopy was gained from Herbert McKay's Three
Dimensional Photography (the influence of which should be evident).  The  first basis and inspiration for Glossary
was W.C. Dalgoutte's Glossary, a revision of which appeared in "Technical Supplements #s 21 and 22" to
Stereoscopy, journal of the International Stereoscopic Union.  Several references are also adapted from articles by
David Starkman and Susan Pinsky that appeared in their (deceased) magazine: Reel 3-D News (thanks!). {CFD}

In my own defense, I note that my main contribution was to offer the use of my MacintoshTM small computer and
laserprinter to enhance the typography when Craig mentioned he had been thinking of re-issuing the glossary.
Because our computers were incompatible, Craig "uploaded" the text in segments to the CompuServeTM electronic
mail service, from whence I "downloaded" it.  It was then converted to PostSciptTM laserfonts; a little editing was
done here and there, some to clarify and some to add curmudgeonly and pedantic asides; a few tongue-in-cheek
definitions and comments were added; a few illustrations were added, and a camera-ready laserprint was prepared.

Now that the opus is on Macintosh disk, it can readily be revised and updated. If anyone wants to add to this listing,
or refine what's already there, feel free to contact either one of us.  We'll be happy to credit our sources in the text,
but expect the same generous attitude toward copyright that we have adopted (see below).  Furthermore, anyone
who'd like a magnetic copy can get one for the price of copying and mailing; please specify the word processing
program. The glossary was prepared in Microsoft® WordTM, version 5.0, but can be provided

in other formats, too: MS WordTM for DOS; Word PerfectTM 5.1 for DOS; MacWriteTM; contact Dale if you're interested.

[2/28/2002: now posted as the 2nd rough edition/appearance in HTML format --and for others to freely download.]

We thank Fred Weitz, Paul Wing and John Dennis for recent Input.

If you would like to cite material from this glossary, feel free to do so; we place no restrictions on its re-use.  We
are vain enough, though, that we wouldn't be offended by being cited. An acceptable format would be:

 Craig & Dale: A Stereo/Photo Glossary (2nd edition).  RWVCo, 1990.

   Craig, [12/7/2001 PMB-123 / 3696 Broadway / North Bend, OR 97459]
   Dale, Minneapolis, Minnesota 55410

  Craig & Dale; May, 1993.


12/31/97: I reformatted this document such that it would be easier to wrangle between word processors, page layouts,
"platforms", and such.  I'm a real chauvinist about double-spacing between sentences [which doesn't work in html editors} and not doing anything special with the left margin (no tabs) --but may have missed a few such changes.  I also eased up on Latin abbreviations and updated/corrected/annotated items I was able to spot in passing.  This work basically remains the "2nd edition", however.  --Craig

2/9/98: * Have now integrated items from "Stereoscopic Dictionary" appearing in the February '98 [Volume 5 #2]
issue of Stereo Views, newsletter of the Cascade Stereoscopic Club.)

* The text files are WordPerfect 5.1dos formatted documents, which most word processors (like
any version of MS Word for Windows) readily recognize and import.

* The images supplied on diskette and via e-mail attachments are the "low rez" set, since the high
rez set takes about 2.5Mb of space and requires a Zip disk or by-your-leave up/download times
via e-mail.

* The last version was spell checked and proof-read, but not for these 2/9/01 additions.

8/3/2001: Now transferred to HTML format and posted. The screen rez images come later (web space allowing).

2/28/2002: Reposted to, giving a bit more attention to typos, formatting, and digital artifacts.  --Craig)

4/25/03: No changes, save for this updated contact line.

7/25/04: I've finally removed the original paginations, bolded the entries, supplied an image of Copilia quadrata, and added a few missing terms. / We express our thanks to everyone who has accessed, used, linked to, and even reposted our "Glossary" --and making it quite visible on the Internet by doing so (to a Google search, for instance). If someone wishes to use this document as the basis for an updated glossary of stereoscopy (and so much has been happening in the past 10 years), you are welcome and need only credit Dale and myself in order to proceed.

5/23/05: Corrections to "Base" entry (and related items), thanks to the alertness and feedback of Victor Reijs.

8/6/2006: At this late date, Craig has finally learned (by happening across it) of an earlier coinage plus trademark usage of the term: "StereoSynthesis" by David M. Geshwind.

6/25/2007: Fixed and updated a number of entries --not really a revision.

We sincerely appreciate corrections and contributions sent in by those who read this web page version of the Glossary.


Trimming Stereo Views
(revised: 4/9/12)

This page is intended to answer common needs and questions about composing stereo (3D) views.

Take the following link for digital file management (using two digital cameras) plus an extended example of how to trim paired camera and "weight-shift" single camera stereo pairs for vertical registration and window: digital trimming".

If terms like "TIFF", "JPEG" and such are unfamiliar, click *here* for a basic tutorial.

With this page begins the overly ambitious goal of imparting not only traditional stereographic "trimming and mounting" skills, but sufficient information to take a run at anaglyphy and "Stereosynthesis" --an art form that's older than photography, since Sir Charles Wheatstone had to draw stereo pairs by hand to illustrate his discovery and descriptions of stereo vision. The invention of a practical camera and photography were still a few years off.

The opening salvo here will try to convey the amazingly difficult idea of "the stereo window" --via simple illustrations, the best of which are Dr. Dale Hammerschmidt's --taken from "A Stereo Glossary".

What's "amazing" is how hard this simple concept is to get across. Those who do understand the "stereo window" (and no special intelligence is required) --are (despite their own initial problems) --consistently amazed at how hard it is for others to grasp.

(See "A Stereo Photo Glossary" for more on this and other terms which are unfamiliar.)

What we have here is you --standing in a room whilst gazing out of a rather small window. When cropping a pair of images ---we try to replicate what each eye sees --though just such a window --onto the world. Each of the two prints in a stereograph corresponds to the view of each eye --the left-to-right extent of what each eye sees --through that small pane of clear glass.

Obviously: because of the different angle of each eye, they see somewhat different "takes" onto the world beyond the window --because the pane is near and the scene is far.

But we'll let Dale explain it to us:

* Stereo Window (of a view): A basically simple concept that for some reason is not intuitively obvious, and causes no end of confusion to newcomers to stereography.  If one views a stereograph, it is generally most comfortable if it is mounted in such a way that one appears to be viewing the three-dimensional image as though through a window. This mythical window is the "stereo window."  If one does not mount stereographs in this manner, the edges often have a distracting "choppy" or "floating" appearance to them.  The way it works is outlined in the following figures, in what we hope to be an informative manner:

As you can perhaps appreciate from this illustration,
an object on the far side of the "window" will appear
to be more to the right in the right-hand image (that
is: have a wider margin on its left side) and more to
the left in the left-hand image (have a wider right-hand
margin). Just the opposite is true in an object which is
closer to the observer than the "window".  [end direct quotes]

When viewing through a window, the right eye sees a bit more to the left --and the left eye sees a bit more to the right. Trimming and mounting stereographs correspondingly will create an apparent "window" through which one views the scene. The most comfortably viewed stereographs are those in which all in the scene appear to be on the far side of the "window". Exceptions can be made for objects which appear to pierce the window pane, as long as they don't cut into the left or right frame edges.

At left is an example of an object )the blob) which appears to be behind the "stereo window". (Use your small "finger lorgnette" or "free view" to see this pair.)

In life (and as Dale's just told us), the blob appears further to the right --when looking with just your right eye. That's simply because your right eye is further to the right --and distant objects appear to "track" with one's moving point of view --much as the Moon "keeps pace with you" while driving along a straight road at night.

BUT: in picture pairs (designed to be mentally "fused" --seen, each, with just one eye) --this "window pane" eye-shift effect is simulated --simply by trimming the two prints inward on their outside edges --as might be needed* to produce the appearance of a close window. (* Real stereo cameras are designed to clip those edges off somewhat right on the negatives.)

Why bother? --Because the picture pair has to stop SOMEwhere --right(??) --and it might as well be done right --else you'll get scene detail appearing to be cut away and floating in front of the window's frame edges --and you end up with visual confusion.

But here we see the blob --clearly in front of the window, and there's no problem in viewing it.

Reason: the object/blob doesn't cut the window's edges. It's "reasonable" that the blob can come through the window --as long as it doesn't tear into the window's frame by doing so.

If you measure the distance between the left and the right appearances of the blob (left edge of it to left edge --say), you'll find that this distance is less than when you measure the spacing between the same edges of each frame. It's now the WINDOW which appears further away --because it appears to be more stationary when your vision shifts from your left eye to your right eye. (Sorry: this "window" explanation might be getting to the point of over-kill for you.)

Computer Stereo:  So what's this "side-by-side" print pair business about --when we're working with electrons, screen phosphors, bits and bytes?

An understanding of how the stereo illusion works is essential to your digital interests --for the image pair is also what you'll be working with when using a computer to create stereo views. When you render a good pair, only then do you "encode" them into (say) and anaglyphic composite (ie: to be viewed with red-blue glasses).

(* If you've read this far w/o fusing the pairs, either stop and learn how to "free-view" or order yourself up a pair of "RCI glasses" and temples --for to wear them on your head. Then you can fuse pairs up to 4" across on each frame.)


We're a long way of from doing anything like "stereosynthesis" or general stereo drawing at this point, so you want to get some stereo camera pairs to work with.

I've included some samples you can work with for now. Just click *here* and *here* to get them, right click to save them to your hard drive or diskette.

For more: scan in pairs from prints, negatives, slides --or get a nice stereo digital camera (and I think you really want a Fuji W3).

Again: you'll be working at "trimming and mounting" very much as if you were working with photographic print paper pairs and an Exacto type razor knife, so you might want to first work with actual photographs. I have "mounting steps" and patterns you can use for that --as well as a 2-hour 3D video.

However: doing your "practice cuts" on monitor images costs nothing when you botch it --and you can try all sorts of crazy ideas that might occur to you --without so much as getting mounting glue on your fingers.

At this point (April of 2002), I'm still advising monitor driver settings of "800 x 600", a 72 or 75 refresh rate, and 24 bit (sometimes mis-labeled as "32 bit") color. However: if you've got an old rig that can't kick out that much imaging, you can drop down to the old 640x480 standard --but try to stay at 24 bit color.

Take "weight shift" pairs with an affordable digital camera --or get those diskettes for a few dollars more at your photofinishing connection. Bringing them in with any pixel count will work, but it's nice to start with images about 450 pixels high (1000 if it's for commercial/prepress work).

If you're using a regular camera, you probably want to hold it in "portrait" format to make stereo pairs --unless your final output is to anaglyphs (or an advanced shuttered format of some kind). Print pairs want to be squarish or tall.


--And now you don't!

Since you won't be working on these screens, I've reduced the pairs to easily fused "6x13" format (as a 640x480 display --smaller and easier at 800x600).

This stupid looking drawing will help you avoid confusion when i refer to scene elements (--and get you into the frame of mind that drawing stereo pairs isn't all that tough).

I've included this drawing (*t2-07.gif*) and two "untrimmed" stereo pairs


--for you to practice on. Simply bring them into your graphics program (Micrografx's Picture Publisher-3.1 if you can find a copy, possibly: Paint Shop Pro (any version), but a comes-with (your printer or scanner, say) graphics program will serve). Then toggle back and forth ("Alt" + "Tab") between your work and this instructional.

Trimming and mounting standards for "Holmes-Bates" format print pairs.


That was the original title for this section --and making/mounting pairs for use in a (could be) 130 year-old stereoscope is a good starting point for creating web page and other computer/digital pairs or anaglyphs. (Hey: you might just want to skip all this computer jazz and make photographic pairs mounted to 7 inch wide cards :-)))

There's not a lot of agreement on standards, even within the Stereoscopic Society of America --except to say that the subject shouldn't be "cut off" by the "stereo window" --and that the left and right images should be mutually level. Let's consider the issues:

"Window Reversal": * Some critics will say your have "window reversal" if any subject matter is seen to appear in front of the stereo window. However, in this section we show how that can be reasonably done.

* Most people who know stereography will use that term if subject matter is seen to be "cut off" by the window. What that means is: there's an impossible relationship in which subject matter that's clearly (stereo-visually) in front of the window, is never-the-less blocked by the frame of the view's window --a window that appears to be further away --maybe even at the view's "infinity" or beyond.

The solution is to cut away the outer edges of the frame pair: some off the left edge of the left frame, an equal amount sliced off the right edge of the right frame. You can easily mask the pair first to see how much you need/want to remove.

"Infinity Separation": This is the actual (ruler) distance on the card between the same item in the farthest distance in both prints ( which items are called "homologous points at infinity").

Obviously, anything you're able to stereograph is less than infinitely distant, but anything more than 100 yards away is as good as "infinity" in normally stereographed views. "Hyper" pairs can reach out much further in conveying depth, but the separation of those distant points --as mounted on a view card, should still be at your "infinity standard" for the kind of cards you're making.

When nothing approaching infinity is in the stereo view at all (an interior shot, say), you might want to set the furthest subject matter to less than infinity card separation, but that's not important.

In these illustrations, the Sun is a safe bet for stereo infinity, ya?

While left-to-right distance between similar left-right details isn't something we worry about in anaglyphic views, they begin with good pairs in which this (as well as leveling, "deviation" (stereo content), and "window" practice does.

Normally, you trim a pair for a good "window" (defined by the two frame lines in my illustration --which represent the edges of two borderless photos), then mount them onto the card such that the Sun-to-Sun distance is within some tolerance.

For use in a traditional stereoscope, traditional opinion places that distance at some low value like 78mm (3-1/16 inches), but theory allows a separation up to about 89mm (3-1/2"). For practical use, the targeted separation should be about 81mm (3-3/16") --or less.

Now let's relate that to a monitor display.

(Use your red-cyan/blue glasses to view this anaglyphic stereograph.) Instead of approaching life-like "parallel vision" (ie: one's eye's looking straight out into the far distance on a view card or stereo slide pair), we sometimes make an anaglyphic composite in which our eyes are always converged at about the distance of the monitor screen (plus or minus). This produces a visual effect known as "puppet theater": miniaturization of the scene in apparent size and depth, but few of us notice or care since our "mind's eye" judges a view's verisimilitude by its own implicit standards.

So "puppet theater is easily tolerated and even "cute", while side-by-side pairs on a monitor screen or something techie-klunky like liquid crystal shutters can be difficult to control and view. It's my opinion that anaglyphs are the only way to go for good and practical-to-post anaglyphy.

Another advantage of SVGA display and anaglyphy is the delightful ease with which such images can be integrated with text --whereas stereo pairs require that any legends near the pair be treated or placed in some specific way.

So once you've selected your separation and gap, you've also selected your (approximate) print width.  The pair can be considerably narrower --often with pleasing results, but it can't be much wider. To maintain your separation standard, narrow print pairs will (of course) use a wider gap.

The height of the pair is up to you: whatever suits the subject and the card stock.

* For working graphics on a computer and monitor screen, we place the pair as close as possible --such that we can work images as large as possible AND while seeing as much pixel detail as possible. That limit is about two 4 (actual-on-the-screen) inch wide images --viewed/fused with an "RCI" lorgnette (though somewhat less might be more comfortable).

If you're running your monitor at a 600x800 scan rate, then you'll probably have to view your (desk jet) printer resolution (300 DPI) or commercial resolution (about 450 DPI) pairs at an even 25% (or: "1:4") reduction --enlarging to 100% from time-to-time in order to fix small details.

Possibly, you have an excellent monitor which can usefully display at 1024x768 or higher scan rates. In any event, set your original pair to a rational TIFF resolution of (say) 300 DPI, then display it at an "even" division --like 50% or 25%.  An odd-ball resolution of (say) 467 DPI won't cut evenly in half at (say) 50% --and you'll end up with confusing depth artifacts and "depth jaggies" in your display.

Upon completion, you can spread out the pair for whatever gap you want to use.


--at 50% transparency.

Here I've completed the project by filling with gray at zero transparency, cutting away the excess card area. While this appears to be (and is) two trapezoidally trimmed frames on a card, I think you can appreciate how the frame lines are nothing more (or less) than scene elements. The frame lines describing the stereo window might be circles, ellipses --or even follow the contours of nearby subject matter in a view (which can be eerily effective for impact).

Obviously, computer graphics programs are far better suited for such fancy work than are a ruler and an Exacto knife(!) --but not all graphics programs.

You will see reported here which programs are suitable for stereoscopic work --but I'm here to tell you that my first run graphics program was created in 1992 by Micrografx: "Picture Publisher 3.1". So far, nothing's equaled it for intuitive operation and exacting work. It still operates in a pentium and W-95/98 or W-XP environments, but some of its ability to format compressions are crippled in W-98 and some of its advanced features (like "advanced editing" for creating anaglyphs) are lamed using either operating system. You'll need a copy of PPub-8 (or higher) to do everything.

The "Template" Mounting Steps
For Open Or Closed Mounting, Using Separate 3 Inch Or Wider Prints
(revised 5/01/2012)

Welcome to "solid image" photography.  I hope the following steps will be clear, lead to years of enjoyment, creativity, and practical applications.  It's very hard to get prints made when using old stereo cameras (Realist, Kodak, Nimslo, Image Tech, etc.), so we must use either Loreo type cameras, synchronized ordinary cameras (film or digital), usually in portrait orientation, and order 3x5 prints to work with (4x6 for Loreo). A 3rd option is to use one of the new Aiptek or Fuji 3D digital cameras (see them at, print out or output a JPEG to be printed with the "Stereo Photo Maker" program, after which you can simply print them at an in-store kiosk or over-the-counter service. (Which ever paths you take, try to keep all subject matter 4 feet or further away for your first efforts. You can get into macro-stereo later on.)

* These steps are for making traditional 3.5" x 7" open mounted cards, although the "Q-VU-X" template also turns out pairs suitable for Q-Vu-x closed mounts (if you have any).

It's best to scribe the patterns (below) onto hardware store "window plastic", using a ruler, drafting triangle, and your razor knife, then use the plastic rectangles as your cutting guide edge.

a)* For Stereo Photo Maker and Loreo pairs, printed out to 4x6 borderless glossy prints, trim the "X" template to a 2-3/4" width --although SPM pairs can often be simply trimmed out as is and mounted --starting with steps "b", "c" --and then jumping to Step #07.

* For standard (SSA/Holmes/Bates) viewcard trim & mount work using separate prints 3 to 4 inch wide prints, use the "X" template as is (but you can equally shorten or narrow the print pair afterwards).

b) Draw a lightly penciled horizontal guideline about 1/8th inch from the bottom edge and mark its exact center.

c) Apply aggressively sticky plastic carpet tape to the backs of the prints before they're trimmed at all (leaving the outer peel-off paper on). Don't tension the tape as you apply it, but neither let it buckle (or overlap).

01) Lay out the entire batch of prints, matching up pairs and lightly marking the backsides of the "lefts". Place a minuscule bit of "office tacky clay" (stationery store item) in the template's circles. (The clay rolls off the prints and dry fingerprints wipe off too, but at some points you might want to wear a cotton glove on one hand.)

02) Pick a pair of prints and lay the templates on them.  Level them using any reference: the image horizon or the print edges.  Keep the templates reasonably square to this reference throughout the steps with the grid side down and the legend at lower right.

03) Find any point of detail and place the same HORIZONTAL line of each template over the same detail in each print.

04) Find and check a second pair of points (well to the left or right of the first pair) that's already under or near any horizontal line.  Adjust one template, if necessary, to make them agree.

05) While maintaining the correspondence of steps #03 and #04, find a detail in the part of the picture that was closest to the camera.  The "stereo window" will now be located at that apparent distance --or closer. Place the same VERTICAL line of each template over this same detail in each print. (Move either of the templates an extra 1/32nd of an inch or so closer to the other for a closer window.)  Press down on the tack circles (careful: don't let the templates slip) to secure their positioning. You can preview the pair if you like with stereo glasses or by "freeviewing" them.

06) Work on a sheet of plastic as your cutting table (or get a made-for-the-purpose "cut-upon" from a scrap book crafts supply shop) and trim off the excess print areas with a Hyde or similar brand "snap-away" razor knife. (Have a safe "sharps" jar to put used blades in.) Use the template edges as your guide. You can make your open mounted pairs smaller by trimming EQUALLY off the same edge of each print.

07) Lay the print pair side-by-side with some gap between them and measure the span between identical details in the distance. When that span is 3" to 3-1/4", the view will "scope" well. Now you know what gap to go for.

08) Remove the templates, clean off any tacky clay, peel off the carpet tape's protective paper, then lay the prints on the card with their bottom edges true to the horizontal guide line, spacing the prints to either side of the center mark to get the desired gap between the pair.

(2-3/4" wide for pairs printed to 4x6 prints)

Template construction

Create a pair like this out of hardware store window plastic. Measure out and scratch in the grids with a scribe.

Happy Shooting!

So: You've got a digital camera :-)
(major revision: 12/19/03, minor revisions: 4/9/2012)

9/15/2010:  Throughout these pages you'll read laments about the loss of Micrografx's "Picture Publisher" and "Designer".

Interestingly, there are now several web sites where you can download PPub in the last version #10. Possibly this is a limited "CE" (or some such) version, but it allegedly installs and runs well on Vista and Windows-7. (Be sure to enable XP legacy mode/s.) The full Pro version is sometimes available through (and you might wish to read the customer reviews).

* A good general purpose graphics program which is both free and in current development is "". Download it at:

* Another option is "Gimp". This is written for Linux operating systems and the authors/home site appears to take no responsibility for how others might port it to Windows and MacIntosh. I've got good reports about its performance under Windows-7 (and presumably on earlier Windows systems) in version number 2.6.8. (You don't want 2.6.9) --but: when I tried to use Gimp it gummed up the works in my PC.

Get it via:

See the "Working With Digital Images" page for programs which are made for working with stereo images.

File Management (for paired digital cameras):

1) Label one of your cameras "Left" or "Right" and use it in that position.

2) Typical digital cameras (say: a pair of Sony DSC-P71s) has an internal clock and conveniently assigns each image file the time of day --to the second. Don't expect your cameras to keep the same time, simply reset the faster one (occasionally) behind the slower one. After each shoot, when you "debrief" your cameras --transferring their memories to your hard drive, note the current time difference. Create a simple text file (say: with Microsoft's "Notepad" or "Wordpad" programs) which bears the name "Rt-__sec-faster.txt" --or some such, then save it to the directory (or: "folder") for the right camera's images. (See the example highlighted file in the lower right of the following image.)

This is a screen-capture of the file manager program "Servant Salamander" (which is still a free download, last I checked). It's the nearest approximation I can find of the terribly missed and long lamented "Windows File Manager" program --which we enjoyed using under the old Windows-3.1 operating system. (It appeared to be identical with the even older DOS/GUI "Central Point File Manager" program --presumably bought out, then shit-canned in favor of that cascading windows abortion: "Windows Explorer". You can easily find and use the old W-3.1 File Manager program, but it won't handle today's long file names.)

[We've since set our cameras such that the their clocks are well synched,  but their frame numbers are way different and continue to diverge. Then we put the frame files together in the same folder/directory, bringing the pairs together via a "by time" sort.]

My wife Peg runs the left camera, I (Craig) run the right camera --unless just one of us is tripping both cameras (when they're mounted on the short bar). (See this link for more details.)

Note the two highlighted image files. They're obviously a pair.

** Alternatively: If your cameras permit of the frames being serially numbered --spanning chip erasures (as do Sony cameras), then let the more heavily used camera get well ahead of the other --such that there's no danger of one camera's output over-writing the others in the same folder (directory). If you keep your camera's clocks well synched, the left and right frames will line up together (when sorted by time).

(For cameras that assign time based file names to frames --or for cameras which number each series of exposures from "#1", then (obviously) you must use a side-by-side directory display --per the above example.)

* That "DS4" file is from my Micrografx "Designer" program (version 4.1 here) which I use to composite all of my printer-ready pairs onto virtual card mounts. You might wish to get the current version of "Designer" or a similar program --in order to make "monolithic" (one piece) view card printouts. I have despaired of creating a tutorial because it will be obsolete (with respect to the devil's dance of revisions in graphics programs) by the time you happen across it. Instead, I'm offering old fashioned "trim and mount" steps:


--done with an exacto knife, matboard mounts, and some kind of adhesive (double stick tape). (There will soon be a "6x13" version of these steps.)

* To prepare the pairs, I use Micrografx "Picture Publisher" in two versions: 3.1 and 8.0.1 (still good enough to keep up with the graphics world's new formats, has horse-shit auto-masking, will annoy you with it's non-alphabetical file formats list, will try your soul by suggesting that you've modified an image file when you haven't, and then there's the need to constantly deal with combining "floating objects" --which don't always seem to settle precisely where you want them).

** The 1992-93 version 3.1 is the best thing Micrografx ever put out. It cost me nearly $500 in 1993, and that was a big reduction from the 1992 price of $800. It beat the pants off of Adobe Photoshop, it melds perfectly with Micrografx's Designer-4.1 (another big chunk of cash at the time) and remains tops for graphics scut work to this day. It won't handle the newer JPEGs and some of its advanced features (like algebraic photo pastes, which I used for making anaglyphs) are lamed in today's Pentium + W-95/98/XP environments.

I've searched and searched --can't find copies to buy. I've several times written to Micrografx --and later to Corel, seeking permission to replicate their program here (to no avail). PPub-3.1 treats masking differently in that you work with outlines ("arcades") which describe objects that you can subsequently move copies or cuts of in a very controlled, even calibrated way.

* I tried to determine if this work can be done with "Paint Shop Pro-7", but by the time I was working on an approach, out came the much changed version #8 (then 9, then the 48 bit 10, then apparently to be abandoned by Corel) --so my tutorial screen captures and techniques would have been obsolete from the start. I've also tried more recent editions of Adobe Photoshop (which product seems to have taken a hit in its "elements" version), the excellent, well designed (and affordable) new 48 bit program "Picture Window Pro 3.5", and even the Russian "Picture Man 5".

Earlier I tried Corel's "Paint" (sunk months into it) and half-a-dozen lightweight graphics programs.

It seems hopeless. One of these days PPub-3.1 will stop working altogether as Microsoft's operating system continues to mutate, so I'm looking into have a now ancient 486-DX based computer specially built for me that runs under Windows-3.x.

I have my doubts about PSP's masking capabilities for monolithic work, but it should be great for general graphics work. PSP is a wonderful program for image corrections, touching up scanned film scratches, and such. Because it allows me to address Windows image file associations (a pain in the ass to address via Windows Explorer!), I keep refreshing my copy of PSP-7 (last best version?) as my default for opening all image formats.

You can still get the old shareware version of PSP-3.12 at many web sites --such as:

--and it's a decent program.

The basic image:

Assuming that the CCD imaging chip offers that much actual resolution, set your camera to save images with minimum JPEG compression ("Fine") and 1200 pixels on the vertical --by whatever minimum horizontal resolution is available (often 1600). If you camera can be set to save without compression --and you've purchased lots of memory, then go that way.

1200 on the vertical is enough for commercial process color reproduction (should your work ever be selected for that) and plenty enough resolution to support desk top and photo finishing print services. (Find a shop that processes with a Fuji "Frontier" machine --a real honey that kicks out 8 lines per millimeter and no images structure: as good as I ever got out of my own color darkroom.)

* Once you transfer your images onto your computer's hard drive and start working them, always re-save them as TIFFs, BMPs, or some other "non-lossy" 24 bit color file format. If you re-save to JPEGs, your images will suffer serious degradation. (Exception: you of course make a separate JPEG copy for use as e-mail attachments and web page postings.)

* The first step in working a digital pair is to open first the right, then the left frames, copying each and placing them together into your (say) Holmes/Bates format 3.5" x 7" card size image space (a "TIFF" image AT 300 DPI).

* When you place the right image you'll have to reduce its size --per the displayed ruler above the card image --and you want about 2-7/8". A good graphics program tells you what finished percentage and/or pixel size that is --so note that number. (That number will likely vanish when you "set" the image --write it down.)

* When you place the left image, first size it to the same reduction you used for the right image, then move it over the right image in order to match it for vertical registration (possibly selecting 50% transparency mode), THEN move it (straight!) back over to the left and set it.

*** NOTE: If you have any intention of outputting your stereo pair to a printed view card, be very sure to work your pair as a TIFF image at 300 DPI and to scale (ie: sized for either a traditional Holmes/Bates 3.5" x 7" card or an "American 6x13" 5 inch wide card (often for free-viewing).  In that case, the header on your graphics program's image pair window is going to indicate "1:4" or "25%" display size as you work on an 800x600 monitor (maybe 50% if you're working at higher rez and/or making a 5" wide card).


* If you create your pair on a 41% gray ground, it stands a good chance of matching Crescent brand "Photo Gray" mat board --assuming that you cut out and mount the pair as chips.

* If you glue your completed 3.5" x 7" (or better still: oversized) card image down onto the mat board --and then trim it together ("monolithically"), then neither the card color nor the ground color is a problem.

Scanning In Your Old Stereo Film

{Updates: I now use the affordable "Canoscan-8400F" --cheaper and better than my old Olympus ES-10S --which no longer works in an XP environment. The LED illuminated 8400G is even better.}

It's important to get that old color print film digitized before it fades --but it's tough to get good commercial scanning service for 5 and 4 perforation stereo frames. Consider purchasing a film scanner and doing it yourself. Three years ago I purchased the affordable Olympus ES-10S ($400.00), but if you can afford it, get a modern 36 bit scanner with "ICE" scratch removal technology (such as: a Nikon "Cool Scan"). ICE is much more than just software. It uses a second, glancing, infrared scan which sees only the film's defects, then subtracts them from the image --NEAT!

But: should you cheap out --possibly buying a used ES-10S for a song, it can do mighty nice work --and Paint Shop Pro's (version #7) automatic scratch removal utility ain't half bad.

Here follows 3 self-legended, gray scale, ES-10S test frames for your consideration. (I removed a lot of scratches so these frames would compress nicely.)

Like most digital imaging, the ES-10S outputs 24 bit color --which is just enough to allow a bit of image correction and still be able to turn out a nice print. Unlike most film scanners, its "D-range" is vaguely described and often assumed to be only "24 bits". According to the manual, the ES-10S uses up to 30 bits internally --but that still doesn't address a scanner's grasp of density range --from which one may choose about 1.5d for a 24 bit color output.


* Don't be confused by "32 bit" color imaging --which often refers to "CMYK" printer ready images --and includes the otherwise redundant 8 bit "K" channel.

* A D-range of 1.5d (beyond the .3d or so film base/mask) is about it for most photographic color prints. (I've measured a 1.8 Dmax on force-dried gloss imaging.)

* It's also about the range of color negative film emulsions --which (accordingly) run at a gamma (or: "contrast index") of about .5 --instead of the .7 or so for black and white emulsions.

In other words, the reach of even a humble scanner like the ES-10S exceeds the reach of most color negative emulsions, answers the tonal range you'd want to make a print, and can drag about the same image out of a negative that you'd be able to produce in your darkroom.

* Black and white negative films and color reversal films run a much deeper Dmax of up to .3d --maybe beyond for astronomical work; so the limits of the ES-10S can be important. But again: to turn transparencies into prints, some of a slide's tonal range often has to be compressed or thrown into black anyway.

Formatting the Digital Stereo Pair
(revised: 9/06/05, additions: 4-9-2012)

(Some of this will seem repetitive, since I've combined earlier pages.)

9/6/2005 up-date: If you can find a copy of PPub-3.1, it will run in an XP environment --better than with W-98. This program is compatible with the instruction below.

3/4/2011: There's a new, free, general purpose graphics program: "", which you can download for free at: is interesting software that's dedicated to editing digital stereo pairs. I purchased a copy, it works fine, it's reasonably priced, but (of course) I'm use to doing it the old fashioned general graphics way --to which I've returned. Newbies, however, might want to patronize and support this company and its worthy ventures.

* Another option is "Stereo Photo Maker", which is a free download, works well, can use Fuji MPO format directly (unlike Pokescope), and is a bit more complex. It easily converts stereo pairs from MPO to side-by-side pairs or anaglyphs and re-saves to your choice of TIFF, PNG, GIF, and JPS or JPG with your choice of compression. You can print your pairs to arch-top stereo card format directly, adding a left-right legend beneath them. SPM appears to be the answer to the virgin's prayer --and capable of becoming the core of a serious stereographic enterprise.

Fuji's W1 & W3 Cameras --and digital age cameras in general

In the Jan-Feb issue of Stereo World (Vol 35, #4), Bob Pfeiff, a seasoned stereographer, wrote a long and thorough review based on his experience with the Fuji W1 --for those of you who are subscribing members of the NSA. (Sorry: Stereo World isn't on-line, but see the above PC Magazine review link as well --even though it isn't as well informed as Pfeiff's.) Except for its redesigned case/grip, bigger, brighter hi-rez display, and the ability to record 3D video in high definition (720p x 24 fps), the innards and menus of Fuji's new W3 stereo camera are said to be the same, so much of Pfeiff's review applies.

I'm better at supplementing reviews than doing the whole job on my own :-) so here are some comments --hopefully with enough extracted/implied thoughts from Bob Pfeiff's review as to be stand-alone-able. Please understand that I own neither the W1 nor the W3, but I do have a copy of the manuals for both to reference. They're downloadable from the Fuji web site, per:

Working with the MPO format:  * I'm not sure what Bob Pfeiffer is in reference to in his review, but from other sources I'm given to understand that the left and right images are separable as JPEGs via either the software which comes with the the camera, or software which comes with the (spendy) "V1" viewer.  Fortunately, there's a freeware (ie: no cost or obligations) program named "Stereophoto Maker" which speaks "MPO" and allows you to work with its containerized JPEG pair --thanks to the hard work and generosity of Masuji Suto San, translation by David Sykes, and tutorials by David Starkman.

Thanks, good people. Download it at:

Bob Pfeiffer experienced slow processing with Stereophoto Maker, but he was using a damnable (IMO) Vista operated computer. Our "Are You Sure?" Vista operated laptop is a lead sled clunker. (It helps to put in more RAM, externally or internally, but file transfers can still be agonizingly slow. We much prefer our up-to-date XP3 PC boxes.)

* So far I've used SPM to pull up a pair from our twinned digital cameras, plus I've opened sample MPOs from:

If the directions for working with separate left-right images aren't working for you, start with "File/Open" and choose "Open Left/Right Images". Be sure not to maximize the window that SPM is running in, since you have to grab a corner and re-size it (along with the displayed pair) in order to fuse the view you're working with (by freeviewing or wearing prism power stereo glasses).

Previously, there were no graphics programs that I could suggest to people getting into working with digital pairs. Aside from Picture Window Pro (which is mostly for running my film scanner), the programs I use are 10 to 18 years old (Micrografx Picture Publisher versions 3.1, 6 and 8; Micrografx Designer 4.1 and 6; Paint Shop Pro-7). I've tried other brands and newer programs, but they didn't measure up --especially to my 18 year old PPub anchor program.

For more about currently available graphics programs, see page "Trim-01".

Returning to PokeScope:

I found it to be quite intuitive. It runs well under my XP-3 Windows operating system and earlier systems. It's available from Berezin --at:

More programs for dealing with MPOs and stereo in general (some for Mac computers) are at:  (Thanks, program authors --and Alexander Klein!)

* I barely know what I'm talking about with respect to computer operating systems and especially "Windows 7", but I gather that there have been 64 bit versions available for some time now. For those of us who have old programs that we love and rely upon, I've been told to opt for the 32 bit version. See:

* Micrografx created Picture Publisher-3.1 back in 1992/93. Originally it sold for $500(!) and until PokeScope, nothing since has come close to its intuitive convenience for doing basic digital stereographics scut work. Try and find a copy --which often shipped as a freebie with old scanners like the Mustek brand. Although it works fairly well in a Pentium/W-98 or XP2 environment, some of it's best features (like for creating anaglyphs ["algebraic pasting"]) are lamed, so you need a recent graphics program as well (PPub or Paint Shop Pro, though PokeScope will at least do anaglyphy for you, and Stereo Photo Maker does it all).

* I've looked at Microsoft's (comes with your operating system) "Paint", and it won't display large images (beyond screen-size in pixel count) to a reduced scale.

* I looked at the 48 bit Picture Window Pro-3.5. It's excellent plus affordable --plus it doesn't annoy you with endless generations of "layers" (you get an annoying series of edit versions instead), but: it still doesn't let you round up and do controlled moves of pixel groups like PPub-3.1 does. I tried the always-available shareware version #3 of Paint Shop Pro (a nice 2 MB download from sites like:

--but decided that its tools are too primitive --even for laying down a side-by-side pair (as you see having been done at the start of my digital steps below). However: PSP-3 still makes a good general purpose graphics program for sizing, histogramming, and printing out pairs for manual trimming.

* I've also looked at Jasc's Paint Shop Pro versions #7, 8 and 9 (went to 48 bits in version #10). This is a wonderful, complex graphics application which, when mastered, should do anything you want --except move pixel groups like PPub-3.1 does. It use to be very affordable (about $40 with rebates from and well under $100 elsewhere) --until Corel got ahold of it and milked it (to death).

I started making a tutorial with version #7, but by the time I got an approach to working with just one "Layer" (PPub-3.1 used elegant masking control in advance of layers), Jasc was shipping version #8 --which was such a departure from the appearance of version #7 that my efforts were for naught.

** So either move to PokeScope, Stereo Photo Maker, or just use any program/s which will allow you to print out 300 DPI color prints to a specified size, then go to:


--and learn how to trim them out --the old fashioned way with a razor knife.

* General note: Don't try to open or create JPEGs (or other compressions) with Picture Publisher 3.1 or other older graphics programs. You need something up to date.

The following steps are based on the use of Micrografx's Picture Publisher version 3.1
There is no substitute. Corel has the brand now and won't sell this old version.
Find a copy if you possibly can. It runs well enough under Windows-98 and XP/2 or XP/3 when you take its option to emulate XP/2 --just for PPub-3.1 (It's a right click on the start icon or the EXE itself to access that feature).

You can, of course, make other modern graphics programs (like Photo Shop Pro) do this work, but you have to fight modern times "bells and whistles" to get through these simple tasks. (The software future belongs to publishers who will provide a "console switch" --to emulate earlier versions of their applications.)

Here are two common problems we deal with when composing a view based on a "weight shift" pair. (See Glossary for any unfamiliar terms.)

(Later installments will address problems with differential rotation and image scale problems, so for now: keep your camera level, leave your lenses at full wide or full zoom, and lock the focus if it's jittering.)

Here's what I did to fix this Beach Driftwood pair (stereographed by Peggy Daniels).

This pair is a nice view but it presents a little extra work for our eyes to do  :-)

The first problem is obvious --by drawing a mask to check and see if details are level (ie: in vertical registration). If not, you can move the mask with your up-down arrow keys (with Micrografx Picture Publisher version 3.1*) at 100% size or 200% size to find out how many pixels one of the frames has to be moved. In this case, the right frame should be dropped 3 pixels.

After making that determination, put a mask just inside the image area of the right frame (so you don't get any "card" color) --

--select it, and choose "cut out image" (PPub-3.1 vernacular) or "move image" and then drop the image down exactly 3 pixels (3 pokes at the down arrow --using PPub-3.1). In PPub-3.1 you then double click outside the image area to settle the moved area. (In other programs you next have to mess around with combining this moved image from being a "floating object".) That leaves a 3p high white space above the frame/image.

Now re-select "Mask Only" and drag the left edge out across the left frame (and settle the mask).

I'm using 2x ("200%") magnification here to move the bottom edge of the mask up just into the left frame image area. (Be careful to move the bottom mask edge --not the whole mask.)

Having used that medicine dropper "color picker" to place the "card" color into the active painting frame (bottom left most area of this image), I next set the mask select to "outside" (using PPub-3.1) and began painting over those frame/image areas that are outside of the mask.

And here I've just about finished up with this step.

But there's another problem --which should be apparent to an experienced stereographer's eyes --simply by trying to view this stereo pair. Even without viewing them --as is plain from the last detail we examined and the one circled here, there's more near image area at the left edge of the left frame --than at the left edge of the right frame. Also: there's more near image area at the right edge of the right frame than at the right edge of the left frame.

What that means is that the frame lines --which define how far away the "stereo window" appears, need to be adjusted. (see "A Stereo Glossary" for this term and anything else which is unfamiliar at: Glossary ). The "window" in this view is further away than and "cuts into" the nearer image details.

An easy way to fix this problem is to place a mask over the pair --such that it cuts off the outside edges equally --and just as much as you need in order to "nick" into nearby image details --more of which can be seen in the other frame.

Then you use the color picker to make the active color patch (lower left of this image in the program PPub-3.1) the color of your "card" --and paint out the image areas which are outside of the mask (as we did before).

Here's the result:

Outputting your view as a traditional ("Holmes/Bates") stereograph

Well --duh: just print it, right?

Most standard stereoscopes (including the "CedarEdge") have "base-out" prismatic lenses with optical centers separated by about 3-1/2 inches (89mm --and the antique ones had to be built that way). With a view card placed on the stage at full focal length, that much distance between similar details (left to right frames) on a card are fusible, since your 2-1/2 inch (64mm) eyes can look at it with no more than parallel vision.

(The technical term for similar details is: "homologous points".)

HOWEVER: folks like to "crowd in" on a good view (to get closer and "see more") --thus defeating the prism power of a stereoscope. Good practice is to "trim and mount" (virtually on a computer graphics program) such that the furthest image detail spans (those items furthest from the camera) are no more than about 3-1/4 inches apart (83mm) --and many members of the Stereoscopic Society of America mount even closer together. Almost no one notices if the maximum card spans are on the order of 3 inches (say), but many people object if you go over 3-3/8 inches. (Some plastic lorgnettes, like the AO and the "RCI", can span up to 4 inches to accommodate "super views".)

Now factor in a bit of "gap" (technical term: "septum") between the image pair --which is an excellent idea (to prevent "retinal edge rivalry") --say: 1/8 inch.

* In a "normal" view (4 feet to infinity, taken with a Realist or similar stereo camera), the range of depth within the view (technical term: "deviation") runs from the span between the window's edges (which are also the print pair frame edges) to a tad more separation between similar points at infinity: about 1/4 inch --if most of the 5 perforation frames are enlarged about 3.5x for the print pair.

** So: if we make our print pair 2-7/8 inch wide (each frame --any height), if we allow for up to 1/4 inch more for the deviation content, if we allow for a 1/8 inch gap --our stereograph is full-up.

Even though we might not be using anything remotely like a Realist stereo camera, even if you're making appropriately spaced hypers and hypostereo pairs --if you make your print pair with 2-7/8 inch wide frames AND trim/window properly (per the directions on these web pages), you'll be turning out "standard 'scope OK" views nearly all of the time.

* Your mounting cards, of course, should be 7 inches wide and normally about 3-1/2 inches high --but up to 4 inches high works well too and fits most Society traveling folio boxes. Sometimes circuit members make extra tall views and hinge them at the septum --to fit into a folio box or maybe to carry them around in a shirt pocket.

* For actually and accurately placing a ready to stick down (glue or carpet tape on their backs) --trimmed print pair onto a 3.5 x 7 inch card, you might want to make a mounting jig --like this one.

Mounting jig
(That ruler isn't a part of it, and sorry for the uneven lighting.)

* The OTHER format is "American 6x13" --which mounts up (typically) on 5" wide cards (just heavy photo paper is often rigid enough) and is over-all about a 71% reduction of a standard stereograph (or: "viewcard").

You can easily turn out both formats on the same "view" (taking that to mean the entire card or folder artifact) by simply reducing a copy of the Holmes-Bates original and placing it on the 3rd panel of a "folder" (see below) as a viewing option.

Here's how to do it almost totally with your computer:

What you're looking at is a sheet of 24 pound wt. standard ink jet stationery (Hammermill 97% reflectance), now trimmed off to a 7 inch width and a length suitable for placing the tri-folded panels into a standard stereoscope --as if it was a Holmes-Bates (Society standard) card-mounted stereo view.

To get images placed just where you want them on the page, you need a "designer" type program --like Micrografx's "Designer" (and I still use their 16 bit version 4.1 here).  The images are worked in a graphics program (like Micrografx's "Picture Publisher" or "Paint Shop Pro", then imported, placed, and (if need be) sized.  Text is typed in with the designer program and the whole is saved as a designer file for future use (and maybe as a template for your next view project).

The main view image is sized to 3-1/2" of height, but the middle panel is as much as 1/8" shorter --such that the gray ground "bleeds" a bit into the adjacent panels.  That saves you the stress of getting both image edges and fold lines exactly the same.

The sheet can be used as is by folding the panels as needed.  Alternately, the top panel can be folded back and permanently bonded to the view panel (using indoor non-reinforced plastic carpet tape) --such that it becomes much more rigid.

Obviously, the panels are "corner rounded" (see glossary) when folded together.  They match along their edges almost perfectly, since they were also trimmed to size when folded together.

Note that the 71% "freeview/6x13" version allowed for placing a small map image alongside --which also includes an arrow designating the scene's location --along with its latitude and longitude (thanks to DeLorme's "Topo USA" program and resource disks).

(Back to Trim-1)

Here are the steps for getting print pairs out of your new Fuji-W3 stereo camera

Considerations:  A year ago I was able to take a Stereo Photo Maker (SPM) generated batch of side-by-side JPEGs to a local over-the-counter processing service and fit the pairs inside the 6 inch width of a standard 4x6 print (which left some blank space above and below the pair to trim away) --but no more. The counter-top processor interface insists on filling out the 4 inch height. Consequently, you'll have to use SPM (as intended) to output a complete, high resolution view, which is imaged within the space of a 4x6 inch "card"/print (ie: a "monolithic view"). For you old-timers, the result is a Grand Photo style "ready to view" pair.

* Don't worry: it's easy. If you want, you can still trim out the pair, adjust the window, and mount to a traditional mat board card.

* Another option is to simply run the SPM generated pair to your desktop printer. SPM shows the pair's placement on a standard 8.5 x 11 inch sheet, should that be your medium/format of choice, or if you're making a "folder" type view (like those used in the SSA's "Letterbox" circuit). The steps here are the same for folders. Just fold the paper, instead of trimming out your printed view. (You might want to print some extended legend text on the page before folding.)

1) Download and install "Stereo Photo Maker" from:

2) Make sure that you've read the Fuji manual's "Camera Q&A" plus pages 1 through 4. Set the camera's date and time, learn how to prolong the camera's display time (page #), do an initial run-through of what the icons mean (book mark that page), and make sure you've read the section on batteries, so that you start fully charged (page #15) --especially before you do your setups or format a memory card.

3) A charger came with your camera. Make sure it's not been tossed out with the packaging. Use it now.

4) Read Page #9-10 and install a memory card of the recommended type and quality. (You'll need a good one --an SDHC, if you decide to shoot video later on.)

5) Read page #11 and carefully format the card before you use it.

* Format it again after you've stuck it into an SDHC capable card reader/adapter --which USB connects to your computer. That's the cleanest/bestest way to erase the card and start fresh (after you've archived your shots).

* Note that your camera's default settings number each new photo to sequentially ("continuously") higher number, independently of changing out or reformatting memory cards. Don't change that setting.

6) The camera default settings work great for general shooting, but you'll want to change a three of them (now).

* On page #64 are shown your photo size and format options. The one you want is "L4:3". Go to page #60 and learn how to change to that size from the "L16:9" default.

* On page #65 are shown the "Image Quality" options. The one you want is "Fine". Go to page #60 again, see how to navigate to that camera setting, and change it from the default "Normal".

* One of the Menu setup options is titled: "MPO 3DREC". Change the default "MPO+JPEG" to just "MPO".

Read page #15 ("Taking 3D Pictures in Auto Mode").

7) Read page #17 on holding the camera --learning how to hold it steady while keeping your fingers and the strap out of the field of view.

8) Read page #19, so you know what the colored lights and messages mean.

** Skip any "advanced" information or settings for now. Master the details and features of "Auto Mode" first. Run through several "rolls" of digital "film", until the camera's functions and handling become second nature.

9) Take a bunch of stereo photos.

10) Read page #12 and #20 --so you know how to review your shots --and delete the ones you don't want.

11) Skip installing the Fuji comes-with software onto your computer.

12) Turn on your computer. Let it boot up and finish doing all its frigging updating and such --which might take 10 minutes, so get a cup of coffee. (It can be extremely confusing to learn a new program when your computer's operational capacities are being pre-empted by such nuisance "house keeping" operations. The computer's user-owner is given lowest priority.

13) Create or find a suitable folder (or "directory") on your computer's "Desktop" display --for receiving your camera's "MPO" files. Make another directory for your finished, ready-to-print, ready-to-view stereographs.

14) When you're done shooting, reviewing and deleting, turn the camera off and remove the memory card. Place it into your card reader (which might just be a little "thumb" adapter) --that connects to your computer via USB.

* The first time you plug a camera memory card into your computer, your computer should say/state something like: "I found some new hardware" --and you just keep sitting there -keeping your hand off the mouse and the keyboard (no *clicking* ! ).

Time passes.

Your computer might then say something like "I'm working on it".

Finally, your computer (perhaps ever-so-briefly) states that your "new hardware" (meaning the camera memory card) "is ready" --but you just keep serenely sitting there --smooth of brow.

* Your security system might ask if it should first scan the memory card. Either a "Yes" or a "no" is fine--

--and you keep on just sitting there.

* Your computer will probably next display a menu of options about what you want to do next --and you then choose to display the contents of your camera's memory card. (*click* or *click*click*? Microsoft can't seem to make up its mind about how to launch a command. I always try a single click first.)

* Inside will be a "DCIM" folder --which you'll *click*click* on to open it.

* Inside that will be another folder labeled: "101 Fuji" (or some such). Go *click*click* on it.

* Now a damnable thing about Microsoft computers is that they often ship with the file tags (types) display turned off, so you might not see a bunch of image files with number names like: "000-0134.mpo". Instead you'll see just the "000-0134" first part of the names.

* The potential problem is: if you've taken any videos, they're identified with a different tag: "000-0135.avi". (Hopefully, the AVIs will be in a separate "MOV" folder, or some such.) (Again: I don't own a Fuji W3, just a camera manual, so I might be remiss in a detail or two here.)

* If the tags (file types) don't show, and if that's a problem, have someone who knows computers change the "Windows Explorer" settings to display them.

15) So okay: there, probably on your "desk top" screen display of the memory card's folder, are all your image files --and there also is your intended MPO receiving folder --both being displayed on your monitor. You know how to round up and "Copy" (NOT "Move") the image files from the one to the other --right? Then do so.

* Do not reformat the memory card just yet. The images recorded on it are your insurance, should there be some misfortune when dealing with the copies you've placed on your computer's hard drive.

16) Next: open the program: Stereo Photo Maker. You're going to use it for just a few steps.

17) Click on File/Open Stereo Image, then navigate within SPM to your MPO folder in the usual way.

18) Select "Side-by-Side" for the format, check "Show Preview", highlight your first MPO selection, and "Open".

19) Now you're looking at the stereo pair in a program window which can be sized, such that the left-right pair can be made to agree with whatever glasses or free-vision you're using to (optionally) fuse it. Most likely, the fused view looks good enough --just the way it comes up. If not, feel free to play with the adjustment options (learn by doing).

20) Now select File/Print Stereo Card, Then "Holmes Card (6x4 In)" at the default 600 DPI --which will produce dandy results when you either print out the view to gloss paper on your desktop printer --or go the over-the-counter photo processing route at a department store.

21) You want to either personalize or delete the legending content.

22) Next: decide whether to print it here and now (simply doing so in the normal way, hopefully onto some quality paper and with an appropriate printer setting) --or: Select "Save as" --then select a 90 percent quality JPEG format and navigate to that folder you created for ready-to-print image files.

23) Now transfer a copy of the folder with the created JPGs to an empty flash memory --or better still: a CD or DVD --along with the original, virgin MPO camera image files --and their folder.

* This is insurance: an approach to both backup and organization.

* Your computer at least has a CD drive that can also record --right? Open up the program which does that and save the two batches of files to a blank CD-r or (better) a DVD-r disk. (The program you need may have come with your computer --and might be named "Nero" or "Roxio". It's intuitively easy to use. Just wait for it to catch up with your requests.)

* Once you've got a CD or DVD of your original and processed image files (in separate folders), label it with dates, places, names, etc --using a "Sharpie CD/DVD Marker" (only: no paper labels or other types of markers). Put the disk into a special disk album or file it in a protective sleeve --no finger prints.

24) Should you decide to trim out and mount the image pair onto a traditional 3.5 x 7 inch mat board card, then the next steps are *here*.

Basic Digital Graphics Concepts
(touched up 3/03/2006 and partially revised 4/25/03 from the 1997 slide-show original)
Hi --I'm Craig and this "show" is a presentation of "the world of digital graphics" --from my own peculiar and jaundiced points of view  :-)

Micrografx was once the Cadillac of PC graphics programs, so much of my work is still created with their 1992 "Picture Publisher" and 1994 "Designer" (vector graphics --integrated with the bit-map graphics of PPub-3.1). But: I also have and use recent Micrografx programs plus several of those more recognizable name plates like: Adobe and Paint Shop Pro plus ray tracing programs.

There are many and confusing concepts involved in this realm of endeavor, plus the field of topics and format types is being added to by frequent software developments.  The history on these programs and their outputs  has been pretty much defined by what's technically possible and practical.

Whatever you decide to use, it's important to run at least one newer program which keeps abreast of new formats and the translation between them.

Let's start with image file types (or: "formats"). In a way, all file types are image files, since the consequence is some kind of a visual presentation, but we're concerned with those that contain specific shape information --and often other attributes like color, brightness, and included masking information.

Fonts are a special class in that they're resident as a set of vector graphics, either in the program, the printer, or both.  They're often an essential part of technical work and can play havoc when moved to another program that doesn't have them in its repertoire  Odd fonts must be separately supplied when a work is given over to another company for printing or other work.  The most common and trouble-free fonts are "True Type", which scale smoothly and give a good monitor presentation that relates closely to what will be printed.  I consider TT fonts to be "vector graphics" (see below).

Line Art is the earliest and most memory efficient graphic type.  Most graphic formats (such as "TIFF", "PCX", "GIF") support line art in "native" and compressed file sizes.  This is called "1 bit" graphics because a pixel element is either on (black, say) or off (white).  Any 2 "colors" can represent a line art graphic.  This is one of a family of "bit mapped" graphics, so called because its elements are plotted within a rectangular field of pixels (picture elements).  The number of pixels in an image and often the physical size of the field are specified within the file.

Grayscale art is a type of "8 bit graphics" since it contains 8 binary bits of information per pixel.  For gray scale images (black through white), this has been considered sufficient for professional grade reproduction, although more bits may be used to provide more reach or "color depth", perhaps to store shadow details that would otherwise be lost into "black".  (Scanners run 10 bits internally.)

This standard of 8 bits counts in binary fashion to 256 levels/shades of brightness (or gray) and came about because display devices (monitors) and printers can only reproduce densities within a range of about 100 to 1.  When that range is divided into 256 steps, the transition between steps appears to be a smooth continuum.  (A convention of "Post Script" printing is implicit in this.  See below.)

Confusion arises because although a file might contain an 8 bit smooth grayscale graphic, the presentation (an ancient VGA monitor display, say), printer output, or the parent document the graphic's placed in might only support 1 bit or 4 bit ("16 color") graphics. (Hardly ever seen now in the 21st Century.)

"Bit mapped" graphics contain only just so many pixels and resolution.  When a bit map is enlarged such that the resolution of the display or printer is significantly greater than that of the graphic itself, the image starts looking rough and jagged.

Another phenomenon common to all bit map graphics is that when they're manipulated for contrast and such, levels of gray are lost.  You can't stretch the tones too much before you start seeing the gray "steps" and the image goes grainy/motley.

Color bit mapped images are simply the combination of 3 "grayscale" images using --instead of white through black-- the primary colors of red, green, and blue.  They're consequently called "RGBs".  The professional level for color has been set at 3x "8 bit" for many years, though "deeper" formats are sometimes heard of and are used within graphics devices.  Obviously, the permutation of 256 shades (or steps) of R, G, and B yields 256 x 256 x 256 = 16.7 million different color possibilities.  This image "depth" is also called "24 bit color".  While "30 bit color" might refer to a scanner using 3 internal 10 bit color channels, "32 bit color" usually refers to the "subtractive" primaries cyan, magenta, and yellow plus the printer's black ("K") channel: "CMYK".  (Unless one is responsible for actual pre-press final image setting or "color separation" work, the independent graphics technician has no business using, specifying, or adjusting the K channel.)

To create image files that are more manageable in size, the color content might be reduced to 64,000 ("64K") colors, which easily passes for 24 bit or "true color".  By carefully selecting and adjusting the "color palette", full color images are often reduced as low as 256 total colors with fair results (GIFFs).  Each image contains only those colors actually needed to reasonably reproduce the image.

Obviously, an old 16 color "plain VGA" monitor display will garbage up any "continuous tone" 8, 16 (64K), or 24 bit image.

(Unfortunately, recent graphics programs/manuals have taken to referencing 24 bit RGB color as "32 bit" --perhaps to one-up others using standard terminology.)

(Notice how this color image falls apart when enlarged too much.)

Vector Graphics constitute a large family that includes the many "3 dimensional" forms now being used to produce digital animation and rotateable technical illustration.  The basic idea is that all lines proceed from defined points, along defined angles, and for defined distances.  These lines can have 24 bits worth of color definition and many other attributes.  The most exotic form of vector graphics are within "ray tracing" programs which actually define a 3 dimensional environment, its light sources, atmosphere, and assign qualities of reflection, transparency, and refraction to surfaces defined by vector graphic lines and areas.

Simple vector graphics started out as "CAD" (computer assisted design) programs and solved the problem of creating large high resolution works with limited memory.  Their greatest advantage is that such images can be re-sized with no loss of resolution.  Their weakness is that they're devilishly complex in construction and you can't just take a graphic "eraser" to a section you want to trim off.  You CAN, however, distort such images as easily as bit map types.

While vector graphics take up little room on a hard drive or diskette and transfer quickly, they're math heavy and would often "draw" slowly (with old computers) when called up for display and manipulation.  Sophisticated "virtual reality" ray trace creations use to take hours of run time for a single display output, since an entire little universe has to be replicated and interpreted for a particular point of view from "within" it.

A multitude of creative graphics programs have evolved: from an assortment of limited purpose applications (that might not work well from one to another) to feature laden program "suites" that combine functions or at least smoothly switch between among a family of applications.

Traditionally, you'd have a graphics program (Mgfx Picture Publisher, Adobe Photoshop, say) that would work bit maps and offer everything from a poor scanner tie-in to many modes of image manipulation and a finished graphics file output.  This bit map final would be in only one of several formats (TIFF, TARGA, PCX, GIF, BMP and such), but most programs now give you a choice of nearly all formats, both for import and export plus compression options.

That graphic could then be taken into many other applications:  graphics capable word processing, a "designer" type program (Adobe Illustrator, Corel Draw) that can handle bit maps as well as the more usual vector graphics, or a publishing program (like Ventura Publisher or Adobe PageMaker).

Graphics services normally expect to see your image work "encapsulated" into a "page" from one of these programs (say: an "EPS" Encapsulated PostScript or an "AI" Adobe Illustrator file).  Recently, it's become easier (as well as more sensible) to just hand over the raw RGB bit map image file.  (A vector graphic work will be in one of the designer type formats, of course.) (Adobe "PDF" format has popularly replaced other formats for small scale commercial printing, but is seldom used for authoring personal desktop documents and graphics. A word processing format or a "Power Point" type show format is more common.)

Let's review graphic formats and practice one more time:

* Those of us who use a simple (comes-with browser, say) viewer often get ONLY a screen rez display.  Although you might conceive of your image as (say) 2.5" wide for each frame AT a resolution of 150 DPI, a simple viewer or web page display will present a pair of frames that are each 5" wide --and the person looking at it will have to scroll around.  (Even the rotten comes-with-Windows "Paint" program lets one change display scale, however.)

With a halfway decent graphics program, an image at 150 DPI often looks a lot sharper in its hard-edge details than it would (size of size) at screen (72 or 75 DPI) rez.

* When you create art work in "Paint" or a good Designer program, large areas are often made up of exactly the same color value.  "One bit" or "line art" is, of course, made up of either black or white pixels.  When such images are made as or converted to either the "GIFF" or "PCX" formats, they automatically compress --and compress VERY well --often better than if "JPEG'd".  When made as or converted to a "TIFF" or "TARGA" graphics document, they can still be saved in the compressed mode --which applies approximately the same kind of compression as is inherent in PCX and GIF files.  (This is called "LZW" compression.)

* Photographic type, or "Continuous Tone" ("CT") images often have next to no areas that are exactly the same color value.  Trying to "LZW" compress such images might reduce them a tad, and add a lot of delay time for re-accessing them.

Instead, we usually JPEG such images when they need to be compact.  JPEG is a wonderful type of compression that, if you have a good graphics program, allows you a very wide range of choices for the degree and kinds of compression.  Often these choices are mostly made for you and you're presented with "Less Compression", "Normal Compression", or "More Compression".  I suspect that most of us will prefer "Less" compression, because "JPEG" is a "lossy" (not lousy) way to go.  The compression program tries to pick out stuff you might not notice --and throw it away to save space.

        > Once JPEG'd, the discarded information is lost, so save a TIFF version if the image is important to you.

        > If you bring up a JPEG'd image, then re-save it as a JPEG, the image takes 2 hits --and it always shows the damage.  Although "Less" compression might look identical to a TIFF, 2 successive "Less" JPEG compressions will make the image look motley --especially where hard edge details lie against smooth areas.  Always go to the first compression as your source --or save the opened image as a "TIFF".

The TIFF, PCX, and JPEG, formats are not always the same, compressed or not.  There've been a series of developments for most graphics formats and sometimes a TIFF saved by one brand/version of graphics program won't open right in someone else's.  That's where those converter/translator programs come in handy.  (I know you've got a good one.  I use "ViewPrint" here.)

Most graphics formats support both "True color" --meaning 24 bit color: 8 bits each for Red, Green, and Blue; AND "8 bit color" --which is also called "indexed color" and "256 color pallet".  GIFFs, however, are always 256 bit color, and JPEGs are either 256 grayscale or 24 bit color.  (Sometimes a graphics program can't access the grayscale version of JPEGs, and there's really little reason to use it.)

Obviously, if an image is only gray scale, it looks perfect as 8 bit "color" --because there's only one color: black-to-white = gray.



In the interests of attaching photos to e-mail, posting photos to web pages, sending photos to printers (perhaps as an "Encapsulated Post Script"/EPS or Acrobat PDF format file to a commercial printer), and having image utilities well within the contrast ball park. it might be necessary to trouble with your graphics card driver (assuming your computer has a discrete/separate graphics card, but it still has a driver).

I've paid very close attention to gray scale/tracking, contrast gain, and colorimetry equivalents, but strangely, and despite 13 years of computer graphics, I've seldom even thought about "system" gamma --or, rather: the gamma throughput to the screen of one's monitor. My graphics manuals counseled me to adjust my graphics program gamma (dynamic contrast) at 50%, then leave it alone --and that simply worked.

Lately, however, I've noticed significant disparities between the default gamma of my system (which is used for utility displays like e-mail image viewers and special image editing windows) --and the main editing window in my graphics programs --both old and new. Without much of an effort to research the why of it, the problem seems to have been where my monitor driver's gamma --or base contrast-- was set.

As to the regular monitor contrast control, one starts with that at 100% --and you leave it there. The regular brightness control is turned up until blacks begin to budge, then back a hair.

Next you set your office/studio lighting to where you'd normally have it.

At this point you can use the monitor gamma utility supplied with Photo Shop (see PS Helps). That sends a gamma order to your monitor driver (if it's up to date).

Alternatively, find your monitor driver's settings via Control Panel then Display and get on the gamma adjustment. Go to:

--and pick a gamma value to test with. The author argues persuasively for the Mac standard of 1.8, which value cured my graphics problems. He provides a link to a Java applet web page for to double check/confirm your average gamma setting (light to dark). Don't be surprised if that number disagrees with the gamma number you read out of your monitor driver settings, or the number indicated by graphics program utilities (including Photo Shop's).

Modifying Digital Cameras for Stereography
(revised: 8/14/03)

You might be familiar with the Sony Mavica. It's rather large --like a medium format SLR with a large telephoto lens.

We've got one --a real honey, but we also bought a pair of Sony (DSC) P71s for practical shooting and for "have-along" cameras. And we ALWAYS have them when we're out --in our small matching fanny packs.

But, whereas the Mavica is almost livable with its SLR format (the image is dim and you have to leave your eye in the eyecup for a minute), the P71s --with their open-to-the-sky displays are not.

* The P71's zoom-scaled viewfinder and it's essential side light appearances aren't too bad, but I want to to see a review of the
last shot --to be sure. We only get 24 bits of image depth to play with, which is fine for a decent print (100:1 tonal range,
photographic or process color print), but exposing that print properly can be as difficult as doing it at the darkroom easel when
the scene has a lot of contrast.

Our film cameras typically produce negatives and transparencies with 36 bits worth of image (12 per channel --which is what a
professional film scanner uses to capture it all) --or a 1000:1 tonal range. That affords us a second chance to get it right in the

Consequently, I've added (black taped toilet paper) tubes and lenses to our P71s --as illustrated.

The above view shows an upside-down P71
with my cobbled "SLR" adaptation.
Below we see both tubes --now with caps,
which are essential to avoid imaging the Sun
onto your LCD screen.

The lenses are actually a pair of plastic 'scope lenses, turned so that their prism power cancels. That gives 10 diopters of lens power for about a 4" focal length. This assembly, measuring 4-1/8" total length, allows me to operate without me reading glasses (YEAH!!!) and with full access to the camera's menu and review features. (These die/cast lenses are cashiered from the stereoscopes we sell --having been replaced with ground and polished ophthalmic pairs.)

This actually improves on the Mavica in that the P71's screen is nice and bright --even without the broad brimmed hats we normally wear to fend off sunburn.

Twinned Cameras on a bar

Our cameras will often be mounted on a common (1.25" x 1.25") aluminum bar (from your local hardware store) with Peg and I operating at either end of the long one. The medium bar (2 feet) and the short one (minimum spacing = 5" or so) can be held and tripped by one person. With practice, we've been able to get the two exposures off consistently within 1/8 of a second and often close enough to match flag and water ripples.

Unfortunately, I've yet to see a digital camera with "cable release" --which will surely be in the form of a remote control device --which is still unlikely to trip a pair of digitals in synchrony, since each camera takes its own sweet time to "settle" on focus and exposure. When manually tripping a pair of Sonys, we "half depress" each, then complete the stab after each camera has given out with a beep and a green light.

That indication is very hard to see/notice in bright sunlight and impossible to hear near the ocean --at any distance. Consequently, I move an ear to each camera --whilst maintaining their general point of view (needed to maintain focus and matched exposure). The hardest part is holding one camera half-depressed while getting the other one to beep. It's a difficult skill --until you get use to doing it.

* And it's NOT to worry that the closest spacing is about 2X normal (eye-to-eye) separation. A mild hyper to our stereo pairs looks more "normal" to most folks --since we unconsciously integrate of drifting (body and head in motion) takes on a scene into our over-all perception of depth. Stereoscopic systems commonly operate at about 1.4X, so 2X just looks a little "better".

* Don't purchase a digital camera unless it has a tripod socket (usually a 1/4-20 threaded hole in the bottom). By inspection, you'll see the most reasonable way to drill your aluminum bars such that it's quick and easy to locate and secure a pair of cameras on it. I placed a little washer as a stop plate to locate our Sonys on the side opposite the tripod socket.

To make the actual attachment, you get short 1/4-20 thumbscrews from a hardware store, 1/4" washers, and nuts. Be sure that the thumbscrews don't bottom in the camera socket! Use a nut spacer and/or cut them shorter.

Our Stereo View Sets
(No longer for sale)
revised: August 28, 2012
composed in Netscape-4.7, 800x600 prime, no cgi, no java, no frames
We have hundreds of catalogued views, thousands of negatives and image files. So much more is yet to be added --to what has now become a non-commercial project.
Set 03.11: San Francisco "c"
View-02: Golden Gate Bridge At Dusk
Set 08.30: Oregon - Central Coast "c"
View-11: Yachats' Lava Rock Bridges
Set 08.31: Oregon - Central Coast "d"
View-10: Bliss' Hot Rod Grill
Set 08.32: Oregon - General Coast & Shipwrecks "a"
View-05: The Classic Shipwreck (Peter Iredale)
View-08: Wave Action
Set 08.41: Oregon - Shore Acres
View-01: Garden & Lily Pond
(This is the new "T-5" format. The ruler is for size,
in case your display/monitor is different. In the
old format, the legend is on the back side or "verso".)
Set 08.51: Oregon - Bastendorf
View-01: Bastendorf Area and Coos Head
Set 08.52: Oregon - Sunset Bay
View-01: A Placid Park Scene
Set 08.53: Oregon - Charleston
View-01: Charleston Docs (& verso)
Set 14.02: Oregon - North Bend Fire & Rescue
View-01: NBF&R's New Pumper
Set 44.01: Stereoradiogram Series
View-01: Stereoradiograms
View-02: A Simulated Stereo X-ray Pair
View-03: Simulation Setup
View-04: (5" lateral source head displacement)
View-05: (10" lateral source head displacement)
View-06: (2.5 degrees subject rotation)
View-07: (5 degrees subject rotation)
View-08: (10 degrees subject rotation)

Learn to "Free View"