Hierarchy classification:

1. top of the aat hierarchies
2. Activities Facet
3. Processes and Techniques (hierarchy name)
4. [processes and techniques by specific type]
5. [image-making processes and techniques]
6. [photography and photographic processes and techniques]
7. photographic techniques
8. picture-taking techniques

Anotations

Scope note:

Refers to techniques used to produce the appearance of three-dimensionality in photographs by using two images made at slightly different positions, mounting them side by side, and viewing the pair through a stereoscope or other device. This type of photography was extremely popular in the Victorian period. The process was described in 1832, but the techniques were perfected only after 1856, when a twin-lens camera was designed to take two pictures of the same scene simultaneously. The viewpoints of the photographs were 2 1/2 inches apart, which is approximately the normal distance between human eyes.