Luminous Exitance

2-1-075

Luminous Exitance (at a point of a surface)

The quotient of the luminous flux (dF), leaving an element of the surface containing the point, by the area (dA) of that element.

Symbol: M

Unit: lumen per square metre (lm/m2)

Note: Formerly Luminous Emittance and, in French, Emittance Lumineuse.

Reference: C.I.E. (modified)

Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)

English