density of incident luminous flux with respect to area at a point on a real or imaginary surface
Note 1 to entry: Illuminance can be derived from the spectral irradiance distribution by
Note 2 to entry: The corresponding radiometric quantity is "irradiance". The corresponding quantity for photons is "photon irradiance".
Note 3 to entry: The illuminance is expressed in lux (lx = lm·m−2).
Note 4 to entry: This entry was numbered 845-01-38 in IEC 60050-845:1987.
Note 5 to entry: This entry was numbered 17-550 in CIE S 017:2011.