Hierarchy classification:

1. top of the aat hierarchies
2. Objects Facet
3. Components (hierarchy name)
4. components (objects parts)
5. [components by specific context]
6. [tool and equipment components]
7. camera components

Anotations

Scope note:

The opening that allows light to pass through an optical instrument, whether the image is to be fixed chemically on photographic materials or merely viewed as in a camera obscura. Apertures may be simple fixed holes, or of variable width or diameter achieved by mechanical means. To refer to aperture size settings, use 'f-stops.'