brightness on:
[Wikipedia]
[Google]
[Bing]
[Yahoo]
[DuckDuckGo]
[Baidu]
[findoula]
Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting
Brightness
in Federal Standard 1037C, the ''Federal Glossary of Telecommunication Terms'' (1996) With regard to stars, brightness is quantified as apparent magnitude and absolute magnitude. Brightness is an antonym of dimness or dullness.
Poynton's Color FAQ
{{Authority control Vision Photometry hu:Világosság
Brightness is an attribute of visual perception in which a source appears to be radiating or reflecting light
Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 te ...
. In other words, brightness is the perception elicited by the luminance
Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through, is emitted from, or is reflected from a particular area, and falls withi ...
of a visual target. The perception is not linear to luminance, and relies on the context of the viewing environment (for example, see White's illusion).
Brightness is a subjective sensation of an object being observed and one of the color appearance parameters of many color appearance model
A color appearance model (CAM) is a mathematical model that seeks to describe the perceptual aspects of human color vision, i.e. viewing conditions under which the appearance of a color does not tally with the corresponding physical measurement of ...
s, typically denoted as . Brightness refers to how much light ''appears to shine'' from something. This is a different perception than lightness
Lightness is a visual perception of the luminance (L) of an object. It is often judged relative to a similarly lit object. In colorimetry and color appearance models, lightness is a prediction of how an illuminated color will appear to a stand ...
, which is how light something appears ''compared to'' a similarly lit white object.
The adjective '' bright'' derives from an Old English '' beorht'' with the same meaning via metathesis giving Middle English ''briht''. The word is from a Common Germanic
Proto-Germanic (abbreviated PGmc; also called Common Germanic) is the reconstructed proto-language of the Germanic branch of the Indo-European languages.
Proto-Germanic eventually developed from pre-Proto-Germanic into three Germanic bra ...
', ultimately from a PIE
A pie is a baked dish which is usually made of a pastry dough casing that contains a filling of various sweet or savoury ingredients. Sweet pies may be filled with fruit (as in an apple pie), nuts ( pecan pie), brown sugar ( sugar pie), swee ...
root with a closely related meaning, *' "white, bright".
"Brightness" was formerly used as a synonym for the photometric term ''luminance
Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through, is emitted from, or is reflected from a particular area, and falls withi ...
'' and (incorrectly) for the radiometric term ''radiance
In radiometry, radiance is the radiant flux emitted, reflected, transmitted or received by a given surface, per unit solid angle per unit projected area. Radiance is used to characterize diffuse emission and reflection of electromagnetic radiat ...
''. 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.Brightness
in Federal Standard 1037C, the ''Federal Glossary of Telecommunication Terms'' (1996) With regard to stars, brightness is quantified as apparent magnitude and absolute magnitude. Brightness is an antonym of dimness or dullness.
New meaning
The United States Federal Trade Commission (FTC) has assigned an unconventional meaning to brightness when applied to lamps. When appearing on light bulb packages, brightness meansluminous flux
In photometry, luminous flux or luminous power is the measure of the perceived power of light. It differs from radiant flux, the measure of the total power of electromagnetic radiation (including infrared, ultraviolet, and visible light), in th ...
, while in other contexts it means luminance. Luminous flux is the total amount of light coming from a source, such as a lighting device. Luminance, the original meaning of brightness, is the amount of light per solid angle coming from an area, such as the sky. The table below shows the standard ways of indicating the amount of light.
See also
* Brightness (sound) * Luma (video) * Luminance (relative) * Luminosity * The difference between luminescence and brightness is practically exploited by prism lightingNotes
External links
Poynton's Color FAQ
{{Authority control Vision Photometry hu:Világosság