# 17-21-073

photon exposure

Hp; H

density of incident photon number with respect to area at a point on a real or imaginary surface

where Np is photon number and A is the area on which the photons are incident

Note 1 to entry: The corresponding radiometric quantity is "radiant exposure". The corresponding photometric quantity is "luminous exposure".

Note 2 to entry: The photon exposure is expressed in metre to the power minus two (m−2).

Note 3 to entry: This entry was numbered 845-01-44 in IEC 60050-845:1987.

Note 4 to entry: This entry was numbered 17-924 in CIE S 017:2011.

Publication date: 2020-12