DrT's Beginner's Guide To Stereo Photography
In 12 simple Questions & Answers
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I recommend reading this Tutorial: http://home.att.net/~osps/tutorial/index.htm. It will explain the basic principle of stereo, its history, and also the various ways to take stereo pictures. Some of these concepts are repeated here too. A stereo pair consists of two pictures, one for the left eye and one for the right eye. You can record these two pictures using a stereo camera or using a 2D camera with a shift between the exposures. Even though the two pictures in a stereo pair look very similar, they are not identical. Identical pictures hold no stereo (depth) information. During viewing the left eye must see the left picture and the right eye the right picture. When this happens, the brain fuses the two images and converts the small differences in them to depth.
2. How Can I Take Stereo Pictures?
The Table above summarizes the most common methods for taking stereo pictures. One of the beauties of stereo photography is that you do not need a dedicated stereo camera to take stereo pictures. You can use your existing 2D camera (film or digital), take one picture, shift the camera by about 65mm (2.5 inches, the approximate spacing of the eyes), take the second picture. You have just recorded a stereo pair! If taking stereo pictures with a single camera, a slide bar (I personally recommend the Bogen slide bar, which is very inexpensive, compact and easy to use) will make things easier. When shifting the camera, try to keep the lens parallel (do not converge) unless if you have a reason to do so. For beginners, shift the camera by an amount equal to 1/30 of the distance to the closest object. Be careful to have the two pictures aligned vertically. One limitation of using a single camera and successive exposures is that it is confined to "still life", i.e. subjects that do not move between the two exposures. To overcome this problem one could use two cameras, fired together. This is a powerful but a bit expensive and heavy stereo system. Perhaps the easiest way to get started is to use a simple stereo camera like a Loreo, Argus, Vivitar. These are used with print film and come with a viewer. Some of these are currently available. Or, consider a stereo attachment (also known as "image splitter" or, incorrectly, beamsplitter). This is a device that attaches in the front of a 2D camera lens and divides the full frame into two half frames, the stereo pair. The next step is to use a 1950s stereo camera, which give excellent results but the non-standard film format might be a problem.
3. How Can I View Stereo Pictures? Many times it is easier to take a stereo pair than view it. Depending on how the stereo pair is displayed, there are a variety of methods to view it in stereo, as shown in the following table:
As you can see from this Table, the viewing device depends not only on the nature of the image (slide, print, computer display) but also on the size and arrangement of the stereo pair. For example, prints can be printed and mounted so that their separation is equal or less to the spacing of the eyes. In this case, a simple viewer or parallel freeviewing can be used. Slightly larger prints (3 inch wide) are used in the Holmes' format (like the old stereoviews) and a prismatic viewer is needed to diverge the eyesight. For an even wider size/separation, some type of mirror/prism stereoscope can be used. One popular and compact prism stereoscope that is also used for computer stereo, is the Pokescope. Finally, the two prints can be placed one at the top of the other. This requires a unique stereo viewer, like the View-Magic. With some practice a person can learn to freeview, i.e. see the stereo image without any viewer. There are two variations of this: Parallel and cross-eye. Parallel freeviewing requires that the right image is placed in the right side and the left image in the left side and that the spacing of the infinity points in the images is equal or less than the spacing of the eyes. Cross-eye freeviewing requires that the right and left images are reversed (right image in the left eye and left image in the right eye). There is no restriction on the size of the images. Some people find it easier to use one method vs. the other but with some practice most people could use both methods. Stereo viewing is a favorite topic of mine. I spent considerable time writing stereo viewer books and working on improving 1950s stereo viewers. I believe that good viewers enhance the stereo experience and I have devoted a good amount of space on stereo viewers in my web page.
4. What kind of Stereo Camera do you recommend? Frankly, you do not have many choices. There are no inexpensive, modern, reliable, readily available stereo cameras. A lot of people have started in stereo with 1950s stereo cameras. Despite their age, these work quite well and take very sharp pictures. That's how I got started and that's how a lot of my friends did. Some names to consider: Stereo Realist, Kodak Stereo, Revere, TDC Colorist, TDC Vivid. The lack of automation in these cameras is not as much of a problem as it sounds. One can very quickly pick up the basic concepts and be able to use these cameras with good results. To learn more, I recommend my CD on "Getting Started in Stereo with a Manual Stereo Camera", or my Stereo Tutorial Book, which covers this subject in Part I. Both are available for sale in my stereo catalog. Other choices include the Nimslo, Nishika, and related cameras, the FED stereo camera, the Sputnik medium format camera, the Vivitar, Argus, or related cameras, stereo adapters in connection with a regular camera, or connecting two cameras to fire simultaneously. These choices are worth considering, but you will soon realize that every system, no matter how attractive it sounds at first, has its own set of problems. For a more detailed overview of available stereo hardware, see my Stereo Tutorial Book, part 4, or some other Tutorials in my 3d information site. If you decide to use a 1950s stereo camera you don't really need any accessories, other than film and a viewer. A light meter is nice to have, but not necessary. Use the Table below to estimate camera settings for ASA 100 film. That's all you need to get started.
5. What kind of Film should I use? A lot of people ask where they can buy "Stereo" film to use in the stereo cameras. Well, things are simple. THERE IS NO STEREO FILM! These stereo cameras use ordinary film. You can buy it at most places where film is sold. There is nothing special about the film itself. It is the way the camera uses the film. Instead of taking just one picture, a stereo camera takes two pictures. That's all! With this in mind, you have to decide if you want slides or prints. In the 1950s, color slide film was the king. The stereo industry was build around slide film processing and mounting. But, the last decade or two, more and more people are using negative film to make prints. Digital photography today also favors prints over slides. It is really up to you, but the choice of film (slide or negative) will determine the format you will be working on, and the viewing devices. Also, you might consider something larger than 35mm film, like Medium Format. Or something smaller, like View-Master (YES, you can make your own Personal View-Master reels with a View-Master camera, a cutter, and blank reels - the View-Master camera uses regular 35mm film). If you are using 1950s stereo cameras, my personal recommendation is to use ASA 100 speed film. This allows you to use the camera on a sunny day with the 1950s cameras that lack high shutter speeds. ASA 100 speed is also a low-grain film and low grain is needed in stereo. I personally use variations of Fujichrome 100 for most of my stereo slides.
6. Who can Process my Stereo Slides or Stereo Prints? Any place that develops film (slide film or negative) can process (develop) your roll of stereo film. But there is a slight problem: The format of the 1950s stereo cameras ("Stereo Realist Format" - see below) is not the same as the standard ("full-frame") 35mm format. The Stereo Realist format image size is 24x23mm while the full frame is 24x36mm. So, even though these places can process (develop) the film, they cannot cut it and put it in standard 2d slide mounts (these measure 2x2 inches or 50x50mm in the outside diameter) or they might not be able to print the negatives because of their smaller width. If you are taking slides, you have two choices: 1) Find a place that mounts stereo slides, 2) Do your own slide mounting. Kodak offered a slide mounting service for a long time but it is now discontinued. There are a few places that still offer stereo mounting. Bill Davis has put together a web page listing such places here: http://pweb.netcom.com/~bd3d/3d-labs.html Here, locally (Cleveland Ohio) we are using the services of a long-time stereo club member, Dennis Petti. Dennis will mount realist-format stereo slides in heat-seal cardboard mounts. He can take care of either mounting or both developing and mounting slide film. He also accepts mail-orders from long-distance customers. Dennis can be reached at 440-899-0486, or via email. Doing your own slide mounting is not too hard and can even be fun and rewarding. First you need to have your slide film processed and returned uncut. Make sure you specify "Do not cut/mount" in the instructions. Then reverse-roll the film to remove the curl, cut it, and place it in readily available stereo mounts. For beginners I recommend either the slip-in cardboard mounts or the RBT mounts. If you shoot negative film with a 1950s stereo camera then you must find a place that will make the prints (or do your own printing). Most automated processing machines will not handle this unusual image size but a lot of places can print the negatives with manual control. It is then up to you to mount the stereo prints.
7. What is the Stereo Realist Format? When we talk about "format" in stereo, we should distinguish between two types of formats: the camera format and the viewing format. Let's look at 35mm film first. The table below summarizes the images size in a few common stereo camera formats:
The Stereo Realist format is also known as 5p because the image size is exactly 5 perforations (film sprockets) of the 35mm film. There is also the 4p (or half-frame) format used by cameras like the Nimslo, 7p (European) format used by a number of stereo cameras of European origin, and the full frame 8p format used by most 2D cameras today. Note that in all these cases the height of the image is 24mm (unmasked). It is only the width that changes. When it comes to viewing the film chips that come out of these cameras, one has two options: Either keep them in individual slide mounts (2x2 inches, or 50x50mm, this is known as the 2x2x2 stereo viewing format), or mount them in standard stereo mounts, which have outside dimensions of 41x101mm. These stereo mounts are also known as "Realist format mounts" because they were first used in the Stereo Realist camera system. Note that the openings of these mounts can have different sizes to accommodate the different camera formats. One of my services are widening Stereo Realist red button viewers to view 7p slides and also widening the apertures of the TDC 716 carrier for 7p slides. More about the issue of viewing wider stereo slides click here. Now, this discussion was only about 35mm slide film. We also have a variety of print viewing formats, medium slide film formats, View-Master, digital formats like anaglyph (red and blue), and a number of other formats. No wonder our hobby is complicated for the beginner. The issue of formats is actually related to the fact that, in stereo, we must use some kind of instrument (viewer) to view the results and the type of viewer will depend on the dimensions and configuration of the mounted stereo pair. That's why formats are important in stereo. If you don't have the right viewer for a given stereo format, then you cannot see/enjoy the stereo pair.
8. Who Can Repair My Stereo Camera? In my experience, most 1950s stereo cameras can benefit from an overhaul, after years of use, or many years of non-use. I specialize in Stereo Realist camera repairs. For other stereo cameras I recommend the services of Jess Powell. Jess does not have email but he can be reached at:
I carry Jess Powell's camera repair books and tapes. For using the Stereo Realist my Stereo Realist book, gives some information on basic Stereo Realist reconditioning. This book also doubles as a guide to Stereo Photography for beginners.
9. How can I digitize/print my Stereo Slides? I often get emails from people who want to 1) make prints from their stereo slides, 2) duplicate stereo slides, 3) digitize stereo slides, 4) convert stereo slides to video. A stereo slide simply consists of two slides. There are photographic ways to duplicate slides. That's nothing new. Doing it without removing the film chips from the stereo mount might be a bit of a problem, but it can be done. Same applies for scanning (digitizing) stereo slides, or copying them in video. For those who inherited a large lot of stereo slides and they want to make prints, the easiest and least costly thing to do might be to scan the slides and make prints. But, remember, if you only print one side, then you have a 2D print. In many cases, the impact of a 3d slide is much greater, so this is something to keep in mind. Finally, there are those who wonder if they can convert 2D pictures in stereo. In principle this can be done, but only with lots of hard work. I sell a CD that explains how this is done ("How to do 2D to 3D Conversions" by Dan Shelley).
10. How can I Project my Stereo Slides? If the slides are mounted in standard stereo mounts, then there are stereo projectors from the 1950s which will allow you to project the slides in 3D. The most popular 1950s stereo projector is the TDC 116/716. Before investing money (about $250 to $400) for a 1950s stereo projector, have the following in mind: a). In addition to the projector you need a screen with metallic finish and polarizing glasses (for the audience). b) Stereo projection is more demanding in terms of alignment of the stereo pair. Technical flaws are magnified. c) As a rule, a stereo slide looks better in a viewer than in projection. With these three warnings in mind, stereo projection is still an exciting and interesting experience and a nice way to share stereo with friends and relatives and larger groups of people. For stereo slides mounted in the 2x2x2 system (i.e. kept in standard 2x2 inch 2d slide mounts) a pair of ordinary 2d projectors can be used. Polarizing filters are attached in front of the lenses. A system of 4 projectors can be used for "professional" stereo slide presentations.
11. Where can I find other Stereo Enthusiasts? Stereo photography attracts a small but very enthusiastic group of followers. If I had to estimate, I would say that today there must be about 10,000 stereo photographers world-wide. If we include those who have an interest in stereoscopic imaging (for example, collectors of stereo images) but do not take their own, then the number might increase by 10x. If you would like to interact with other stereo enthusiasts, first check to see if there is a stereo club close to your area (by "close" I would put a several hours of driving time). A list of stereo organizations can be found here: http://pweb.netcom.com/~bd3d/3d-clubs.html Some organizations publish magazines and organize annual conventions. These meetings is a great place to see good stereo, meet other stereo enthusiasts, buy/sell/trade stereo equipment or other collectibles. A summary of important organizations follow:
If you cannot find local stereo enthusiasts or if meeting once a month not enough to satisfy the thirst for stereo, consider joining one of the email discussion lists that talk stereo 24 hours a day. The largest such list is called photo-3d. You can find more details and subscription information here: http://www.photo-3d.org/
12. Why isn't Stereo more Popular? I often hear this question from beginning stereo enthusiasts. Related to this: "Why did stereo lose its popularity?" and "What's in the future for stereo?" Different people tend to emphasize different issues but I think most people agree that stereo is more complicated than ordinary 2d photography. I requires more from the photographer. More care in recording the stereo pair. More care in presenting/viewing the stereo pair. Unlike our ears, which can perceive different sounds without a problem, our eyes are highly coordinated. Misaligned stereo images cause headaches and give stereo a bad name. For every stereo enthusiast, I can find at least two who do not care for stereo. For every photographically inclined amateur willing to try stereo photography, I can find at least 10 photographers who do not care to try stereo. Considering the effort involved, stereo photography will never become widely popular. I think it will always remain a hobby for the few, more dedicated individuals, among us. Looking at the history of stereo, popularity has risen after a major photographic development. For example, the peak of the 1950s is related to the development of color slide film (Kodachrome). Today we are experiencing a digital photography resolution. This revolution is bringing new enthusiasts into the hobby. Whether it will be followed by consumer digital stereo cameras, remains to be seen. Note that digital photography has many advantages compared to film photography in regards to image alignment (can be done with software and could be automated). But you really don't need to wait for a digital stereo camera to come along... There are plenty of cameras, tools and experience to get started in stereo right now!
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Updated: February 2003