- the state or quality of being luminous.
- Also called luminosity. the quality or condition of radiating or reflecting light: the blinding luminance of the sun.
- Optics. the quantitative measure of brightness of a light source or an illuminated surface, equal to luminous flux per unit solid angle emitted per unit projected area of the source or surface.
Origin of luminance
1875–80; < Latin lūmin- (stem of lūmen) light + -ance
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for luminance
A luminance seemed to come from above, from the unseen heights of the magnificent double staircase.Helen with the High Hand (2nd ed.)
A few fluoros cast wan puddles of luminance on the plastic flooring.The Sensitive Man
Poul William Anderson
The remainder of the big room receded into a grey twilight encircling the patch of luminance.The Lamp of Fate
- a state or quality of radiating or reflecting light
- a measure (in candelas per square metre) of the brightness of a point on a surface that is radiating or reflecting light. It is the luminous intensity in a given direction of a small element of surface area divided by the orthogonal projection of this area onto a plane at right angles to the directionSymbol: L
C19: from Latin lūmen light
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
Word Origin and History for luminance
"luminousness," 1862, from Latin luminantem (nominative luminans), present participle of luminare (see luminary).
Online Etymology Dictionary, © 2010 Douglas Harper
- The luminous intensity of a light source per unit area. Occasionally the lambert unit is used to measure luminance. Also called photometric brightness
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.