Creating stereo pictures with only your old faithful single lens reflex sounds a little complex, but if one can live with some pictorial limitations, it does work well.
A few years ago my picture taking ventures took a sharp turn. Although my greatest desire for subject matter had been scenics, especially when on foreign vacation trips, my equipment was solely a 35mm single lens reflex with a good zoom lens. Fast and easy.
Using my camera, I had experimented with stereo by finding a composition I liked and taking two pictures. I took one picture for the left eye, then shifted my weight a little to the right and took the other picture, for the right eye. The compositions are as identical as I can make them.
Mounting the prints on cards - very similar to the stereo cards of the late 1800s - and viewing this card with a classic old stereoscope, I was thrilled with the result. The minor difference in perspective between the two exposures became a phenomenal difference in the viewed stereo photograph its elf. It exceeded my expectations. The human brain magically takes two slightly differing images and blends them, so that we see a single image with remarkable perspective. Some names for this procedure might be 'cha-cha' or 'rock and roll', or just plain 'body shift'. The result is called 'hyper-stereo'.
Basically we are creating stereo cards. Here is the procedure:
Use negative film and make prints. One print of each photograph, (roughly 3" x 3" in size), is mounted on a 4" x 7" card with the left photo on the left half of the card, and the right photo on the right. The prints should be trimmed so they are as identical to each other as possible. The same object on each of the two prints should be about 3 and 3/16 inches apart. The horizontal alignment of both photos should be accurate. The card is then viewed with the stereoscope.
Each eye sees only the photo shot for it, but both together give us a three dimensional view that cannot adequately be described.
There are some limitations, and some advantages.
1) One requirement is that within the subject being photographed nothing should be moving . . . . not people, nor cars, nor birds, nothing, or the stereo pair will not have identical subject matter, and the result will be confusing.
2) Make the composition as well as the framing of each photo as similar as possible, and keep the camera as level as possible.
4) In general, the distance the camera is moved sideways between exposures is more or less dependent on the closeness of a foreground subject. The big advantage of this shift in camera position, (over the use of a stereo camera), is this ability to vary the spacing between the two exposures. For example, where there is a foreground tree as a frame for the scene, and it is say 30 feet away, I might shift the camera eight to twelve inches. When photographing a cityscape where the closest object in the scene is perhaps a quarter of a mile away, one might walk a few hundred feet before taking the second shot.
5) If there are people involved, they must not move between the two shots. I shout "FREEZE" - snap one - move the camera - then snap the other.
6) There is some latitude in taking the pictures, but the card mounting of the stereo pair is quite critical and must be done with precision.
Although considerable effort goes into this stereo procedure, it has presented a whole different standard for scenic photography, a very exciting new standard. It is a new way to look at photos which now, along with height and width, includes a very real feeling of depth. You are there.
All over the world there are many active stereo clubs. One might get help with the process from others using this method.