Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Visual and Verbal Communication (hierarchy name)
4. Visual Works (hierarchy name)
5. visual works (works)
6. [visual works by material or technique]
7. photographs
8. [photographs by form]
9. positives (photographs)
10. direct positives

Anotations

Scope note:

Photographs made by dissolving light-sensitive bitumen in oil of lavender and applying a thin coating over a polished metal plate, or other substrate. The process was invented ca.1822 by Joseph Nicéphore Niépce, and is considered the first process to produce a permanent photographic image from a camera projection.