Assertion: lens's area | /r/HasProperty | covered by hole
Facets:
value: in the diffusion discs
type: LOCATION
value: in sieve aperture
type: LOCATION
Source sentences:
text: An H-stop (for hole, by convention written with capital letter H) is an f-number equivalent for effective exposure based on the area covered by the holes in the diffusion discs or sieve aperture found in Rodenstock Imagon lenses.