The standard measure of light radiation. (For example, one candle emits 12.5664 lumens).
A lumen is a measure of the amount of light produced by a lamp, the light coming out of the lamp. A lamp's light output rating expresses the total amount of light emitted in all directions per unit time. Ratings of initial light output provided by manufacturers express the total light output after 100 hours of operation.
A unit of measure for light output submitted by Fish Newb The lumen can be thought of casually as a measure of the total "amount" of visible light emitted. submitted by Rex Grigg