Stereoscopic Photography (contd.)
Stereo pictures are taken by means of a camera with two
lenses. This provides two separate pictures 6 cm apart, about
the distance between the eyes. Although the pictures appear
the same, they are not. When looked at in a viewer, which has
prismatic lenses, your eyes will blend the two views into one
and the brain perceives it in three dimensions the same as
normal vision.
Wet Plate Stereo camera, 1860