luminance
nounThe condition or quality of being luminous.
nounThe intensity of light per unit area of its source.
nounLuminousness: as, the luminance of the stars.
nounthe quality of being
the luminous flux emitted in a given direction divided by the product of the projected area of the source element perpendicular to the direction and the solid angle containing that direction, i.e. luminous intensity divided by unit area; measured in
the quality of being luminous; emitting or reflecting light
