The first photographs were made around 1838, and a decade later sterographs were being made and sold. The idea sprang from 3D drawings by British scientist Charles Wheatstone in 1832, and applied to the new science of photography by another British inventor, David Brewster in 1849.

Early stereographs were made by taking one picture, and then moving the camera a few inches to the side, and taking a second picture to make a stereo pair. Today some photographers still use a sliding tripod mount to make stereo pairs. Some hackers built cameras with a single lens that slid left and right to take two pictures on the same piece of film. Other craftsmen built cameras with two lenses.

Some photographers mounted two cameras side-by-side. At left are two 35mm Nikon FE2s that I once mounted on a bar with a Y-shaped cable shutter release and a bubble level. Although unwieldy, this rig takes wonderful stereo pairs. By varying the separation between lenses I can create an exaggerated sense of depth when I want. Stereographs made with lenses wide apart make objects look disproportionately small, as if seen through the eyes of a giant.

Dozens of gizmos with two lenses have been made by Kodak, Wollensak, Revere, and at least 50 other manufacturers. The biggest seller was David White's Stereo Realist, which debuted in 1947 and used the newly popular 35 mm film. Made in Milwaukee and later in Germany, about 130,000 were produced until they were discontinued in 1971.

Realists can still be found in used camera stores, antique shops, and online auctions for $100-150 for the f3.5 models. A rare f 2.8 model can sell for twice as much. At left is my 1947 Stereo Realist f3.5. As indestructible as a hockey puck, Realists have excellent optics and take remarkably crisp images. The third lens in the center is the viewfinder for aiming. Unfortunately the top shutter speed is only 1/150 of a second, and the controls are a bit awkward. But a little practice and a good light meter make the Realist a fine tool of expression. And it's a helluva lot lighter than the twin Nikons.

In 1980 the Nimslo camera was introduced in an attempt to popularize stereo photography. It used four lenses to take four pictures for lenticular printing. Production lasted less than five years. At left is a similar but more evolved concept, a 1998 vintage 3D Trio point-and-shoot 35 mm camera. Complete with built-in meter, flash, and motor drive, it took three pictures for lenticular prints and sold for under $200. The manufacturer went out of business within two years. I suspect both failed because the public views lenticulars as a novelty, something from a Cracker Jack box.

Argus currently makes a stereo camera (right) that uses two mirrors called a beamsplitter to create stereo pairs that can be printed in conventional drug store one hour developing shops and viewed with a simple lorgnette. It sells for under $90 including the viewer.

Then there are the hand made precision RBT cameras (left) produced by fusing two 35 mm cameras together. Above is a Burdlo with 12 lenses. If you have to ask, you can't afford them.

Several inventors and garage tinkerers have built remarkable cameras. The latest trend is, of course, digital. I have seen several homemade versions. How long will it be before we see digital stereo cameras on the market?

Click here to see a website with some more designs for early stereo cameras.