By Dick Oakes
HOW TO SEE 3-D: Look "through" the pair on the left. Cross your eyes for the pair on the right.
HOW THEY'RE TAKEN
Since the early 1970s, I'd been taking three-dimensional (3-D) stereo slides -- not with a 3-D camera, but with various standard single-lens-reflex (SLR) 35mm cameras. To do this, I first took a photo looking through the viewfinder with one eye, putting a point of a framing mark (or a dirt spot on the prism!) on some object in the distance. After the film was advanced, I moved the viewfinder to the other eye while keeping my head stationary, aligned the mark on the same object in the distance, and took the second photo. This process has been made easier since the introduction of auto-wind cameras.
HOW THEY'RE VIEWED
After processing the slides, I place the left of the pair of slides into an old Gitzo dual slide viewer for the 3-D effect. This viewer was made by the Gitzo tripod company in Europe, but was discontinued many years ago. It has two single slide viewers mounted on a plastic rail (with thumb screws) and adjustable oculars for focusing. You can get the same effect by purchasing two small individual slide viewers (the kind you hold up to the light to see the slides) and holding them together for viewing with both eyes. (I also experimented with gluing them together, finding I needed to place something under the joint before gluing so that they were slightly angled inward when held up to the light.) If you want to build your own 3-D slide viewer, check out the Let's Build a Stereoscope at the Fun Science Gallery Website. It even shows a novel way of using those two individual slide viewers.
ADVANTAGES WITH THIS METHOD
By using standard cameras with standard film, even if you don't get a good stereo view for some reason, you still have decent standard 35mm slides from which photos can be made. You also do not need a special camera, nor special processing, nor special slide mounts, nor an expensive stereo slide viewer.
PROBLEMS WITH THIS METHOD
If there is anything moving, say foliage from the wind, or people walking, or vehicles traveling, those items will be displaced in the photos and will look like ghosts when viewed with both eyes. On the other hand, the appearance of water movement may be just what the photographer ordered!
HINTS FOR USING THIS METHOD
First of all, you will be amazed at some of the 3-D photos you will create. You will find, however, that there are some tricks you will need to utilize to optimize your success:
THE DRAWBACKS OF 3-D PHOTOGRAPHY
First of all, there's the expense! You'll find yourself taking several photos of the same scene where you might take only one snapshot with conventional photography. Although you do get to select the best of several photos, should you want to make prints to show or put in an album, prints from slides are considerably more expensive than prints made during the original processing or even as copies from negatives. Remember, also, that each 3-D photo takes twice as much film, so the cost of film is doubled. On top of that, if it takes ten seconds to show someone each of your prints, it will take many times more than that to show each of your 3-D views . . . not only do you have to put the slides into the viewers, take them out and file them before selecting another set, and file the previous set, but each person who views your scene will want to take up to several minutes to ooh and aah and babble about the effect you've produced. This means that you'll have to select only the best of a large group of 3-D views to show your friends and relatives--a bummer when you put all that effort and money into taking all those slides!
WHAT ABOUT STEREOSCOPES?
A stereoscope (not to be confused with the stereopticon that used glass slides) is that hand-held device your grandparents used in order to view 3-D stereo photos mounted on cardboard, called stereographs. You can still find these viewers and photo cards in antique shops around the world. On the other hand, you, too, can make your own stereographs. Note that the views I've shown above mention that they are two halves of the same view--those are prints that I mounted on cardboard. What I've done is to taken a 3-1/2x5 print from each of a set of two 3-D slides, sliced them in half, and mounted them on a piece of stiff cardboard cut to size. (For my cross-eye views, I just used a software program to cut and paste the left side to the right.) For some views, you might take only the center of the photo. I purchased a stereoscope viewer on eBay and can now leave a stack of 3-D pictures on a table with a viewer for folks to view at their leisure.
WANT MORE INFORMATION?
Rather than supply several pages of links here, I suggest that you use your favorite Internet search engine to locate Websites that feature information on 3-D. Searching for related words, such as 3D, 3-D, stereoscope, stereoscopic, stereograph, stereographs, stereopticon, stereogram, stereophone, magic lantern, and anaglyph, should give you hundreds of links. On the other hand, you might start your search by going to the 3-D Links page at the View-Master website.