Stereo camera

Also known as: Binocular camera

A stereo camera is equipped with two lenses fixed at a defined distance from each other, analogous to the spacing of human eyes. It records two images of the same scene from slightly different viewpoints. When the distance between the lenses (baseline) is approximately 65 mm, it corresponds to the average interpupillary distance of an adult human. Earlier stereo cameras could have a larger baseline. Prior to the introduction of the stereo camera, stereo pairs were produced using conventional single-lens cameras by taking two successive photographs from slightly displaced positions.

The first stereo camera was patented in 1856 by John Benjamin Dancer. By the 1860s, stereo cameras could be fitted with simple shutter mechanisms. Hinged flaps mounted in front of the lenses or a rotating plate were manually operated to uncover and cover both lenses simultaneously. As photographic processes improved and shorter exposure times became possible, more advanced shutters were developed to provide precise exposure control.

To prevent overlap of the two images on the photographic plate, a partition (septum) was installed within the camera body between the lenses.