It’s difficult to avoid 3D these days. Movies at your local multiplex are in 3D, television in 3D is the latest innovation and Fuji has introduced the first digital 3D camera. But there’s nothing new about three dimensional, or stereo, photography. Stereo cameras have been around for years and are still usable and very effective when you combine their old-time shooting methods with modern digital techniques.
The reason we see in three dimensions is because each eye sees a slightly different view. The brain takes those two views, combines them and gives us the illusion of depth. A stereo camera has two lenses, shooting two pictures at a time. When the pictures are viewed so that the left eye sees only the one taken with the left lens and the right eye sees only the one from the right lens, the brain does its magic and you see a single image in three dimensions.
Finding and Using a Stereo Camera
Early stereo cameras took glass plates. Later, they took roll film. But during a resurgence of interest in the 1950s, many were made for 35mm. These are the best to use today. You can find them at classic camera shows, from specialist dealers, in thrift stores, at estate sales and on eBay.
The one used for this article was an American Stereo Realist, made by David White & Co. Here are its specifications: two lenses to shoot pictures and a third between them to reflect its image to the viewfinder; apertures between f/22 and f/3.5, shutter speeds from 1 second to 1/150 second, and focusing from 2 1/2 feet to infinity. The knob that focuses the lenses is surrounded by a depth of field scale, and its importance we’ll come to soon. There’s no automatic exposure, but that setting was measured with a Nikon D80 digital SLR and set manually on the Realist.
Stereo pictures are all about depth. A picture where everything is in the far distance, or in which the subject is on a single flat plane, does not make good 3D. So the subject is best considered as a series of layers, getting some object strongly in the foreground, including detail in the middle distance and letting the far distance take care of itself. Subjects like bridges, long roads or railway lines receding into the distance make good stereo pictures.