• Home
• Introduction
• About
• Timeline
• People
• Learn More

A Man of Many Parts: The Life and Legacy of Francis Willey Kelsey

Home » Educator » Stereo Viewers for Education

STEREO VIEWERS FOR EDUCATION

Before the advent of cinema and Thomas Edison's 35 mm film camera, many people experimented with creating illusions through images and photography. Pre-cinematic equipment included stereoscopic viewers and views, which took two simultaneous images of a subject from slightly different angles. When viewed through a stereoscopic viewer, the image appeared three-dimensional.

The technological development of three-dimensional photography was also a social innovation. The new ability to share visual experiences gave rise to mid-19th-century viewing parties. Guests at these social gatherings would pass around individual stereo viewers, which permitted them to gaze at distant lands, unique botany, or even art.

Kelsey envisioned another application for these viewers well beyond parlor parties. He harnessed this technology to serve the purposes of education. Reportedly, Kelsey used a larger stereo viewer that allowed students to view stereo cards of archaeological excavations. Perhaps his was an earlier projector model (stereopticon), or perhaps it was self-illuminated like the one here. During this time of rapid innovation, many variations of stereo viewers, opticons, and projectors were patented. Because of this variety the terms are sometimes used inconsistently.

Images for these devices were created on stereo optic cameras, which have two lenses placed slightly apart to mimic the placement of the human eye. Although the images on the stereo cards looked the same without a viewer, when examined through the special prismatic lens, they blended together as they would in three-dimensional eyesight. This fooled the brain into seeing two dimensions in more depth. Stereo cards were popular for 70 years, but new technologies like radio and cinema decreased demand for them in the 1920s.