foot-lambert

or foot·lam·bert

[ foo t-lam-bert ]
/ ˈfʊtˌlæm bərt /

noun Optics.

a unit of luminance or photometric brightness, equal to the luminance of a surface emitting a luminous flux of one lumen per square foot, the luminance of a perfectly reflecting surface receiving an illumination of one foot-candle. Abbreviation: fL

Origin of foot-lambert

First recorded in 1920–25

British Dictionary definitions for foot-lambert

foot-lambert

noun

a former unit of luminance equal to the luminance of a surface emitting or reflecting 1 lumen per square foot. A completely reflecting surface illuminated by 1 foot-candle has a luminance of 1 foot-lambert Abbreviation: ft-L