luminous exitance

M_v; M

density of exiting luminous flux with respect to area at a point on a real or imaginary surface

where Φ_v is luminous flux and A is the area from which the luminous flux leaves

Note 1 to entry: Luminous exitance can be derived from the spectral radiant exitance distribution by

where K_m is maximum luminous efficacy, M_e,λ(λ) is the spectral radiant exitance at wavelength λ and V(λ) is spectral luminous efficiency.
Integral limits can be confined depending on the spectral responsivity of the detectors used as a sensor.

Note 2 to entry: The corresponding radiometric quantity is "radiant exitance". The corresponding quantity for photons is "photon exitance".

Note 3 to entry: The luminous exitance is expressed in lumen per square metre (lm·m⁻²).

Note 4 to entry: This entry was numbered 845-01-48 in IEC 60050-845:1987.

Note 5 to entry: This entry was numbered 17-735 in CIE S 017:2011.