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 produced by mounting a negative (made by a variant of the wet collodion process) that is on glass with a dark backing, which makes the image appear as a positive. Came into wide use in the United States in the early 1850s.