How Were Keystone View Company's Stereographic Photos Produced?
A special camera with two lenses spaced two-and-a-half inches apart (the distance between the pupils of a person's eyes) took two nearly identical photographs. When the photos are mounted on a backing and viewed through a stereoscope the viewer's brain is tricked into seeing the two images as one three-dimensional image.
During the Keystone View Company's early years wooden cameras with glass negatives were used. One of Johnson-Shaw Stereographic Museum's many treasures is an antique stereoscopic camera.