foot-lambert

or foot·lam·bert

[foo t-lam-bert]

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

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

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-lambertAbbreviation: ft-L

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012