Brightness 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.[1]
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[citation needed] (although some of the three
components make the light seem brighter than others, which, again, may be compensated by some display systems automatically):

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.
See also
Notes
- ^ “Brightness” in Federal Standard 1037C, the Federal Glossary of Telecommunication Terms
(1996)
External links
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