AskDefine | Define effulgence

Dictionary Definition

effulgence n : the quality of being bright and sending out rays of light [syn: radiance, radiancy, shine, refulgence, refulgency]

User Contributed Dictionary



From ex- "out of, from" and fulgere "to shine".


  1. A state of being bright and radiant, splendor, brilliance.


See also

Extensive Definition

Brightness (also called effulgence) is an attribute of visual perception in which a source appears to emit a given amount of light. In other words, brightness is the perception elicited by the luminance of a visual target. This is a subjective attribute/property of an object being observed.


"Brightness" was formerly used as a synonym for the photometric term luminance and (incorrectly) for the radiometric term radiance. As defined by the US Federal Glossary of Telecommunication Terms (FS-1037C), "brightness" should now be used only for non-quantitative references to physiological sensations and perceptions of light.
A given target luminance can elicit different perceptions of brightness in different contexts; see, for example, White's illusion and Wertheimer-Benary illusion.
In the RGB color space, brightness can be thought of as the arithmetic mean μ of the Red, Green, and Blue color coordinates (although some of the three components make the light seem brighter than others, which, again, may be compensated by some display systems automatically):
\mu =
Brightness is also a color coordinate in the HSB or HSV color space (hue, saturation, and brightness or value).
With regard to stars, brightness is quantified as apparent magnitude and absolute magnitude.

Brightness of sounds

The term "brightness" is also used in discussions of sound timbres, in a rough analogy with visual brightness. Timbre researchers consider brightness to be one of the perceptually strongest distinctions between sounds, and formalize it acoustically as an indication of the amount of high-frequency content in a sound, using a measure such as the spectral centroid.


External links

effulgence in Bulgarian: Яркост
effulgence in German: Helligkeit
effulgence in Korean: 명도
effulgence in Italian: Luminosità (teoria dei colori)
effulgence in Hungarian: Világosság
effulgence in Portuguese: Brilhância
effulgence in Thai: ความสว่าง
effulgence in Vietnamese: Độ trắng
effulgence in Chinese: 明度
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