Lightness

Lightness is a visual perception of the <a href="/facts/Luminance/yAqK94ny">luminance</a> 
 
 
 
 (
 L
 )
 
 
 {\displaystyle (L)}
 
 of an object. It is often judged relative to a similarly lit object. In <a href="/facts/Colorimetry/CuchJjFL">colorimetry</a> and <a href="/facts/Color_appearance_model/AFlaBhdR">color appearance models</a>, lightness is a prediction of how an illuminated <a href="/facts/Color/XDvW7ESP">color</a> will appear to a standard observer. While luminance is a linear measurement of light, lightness is a linear prediction of the human perception of that light.
This distinction is meaningful because human vision's lightness perception is non-linear relative to light. Doubling the quantity of light does not result in a doubling in perceived lightness, only a modest increase.
The symbol for perceptual lightness is usually either 
 
 
 
 J
 
 
 {\displaystyle J}
 
 as used in <a href="/facts/CIECAM02/sT38xh4m">CIECAM02</a> or 
 
 
 
 
 L
 
 ∗
 
 
 
 
 {\displaystyle L^{*}}
 
 as used in <a href="/facts/CIELAB/jxx4j975">CIELAB</a> and <a href="/facts/CIELUV/E8eGBnBS">CIELUV</a>. 
 
 
 
 
 L
 
 ∗
 
 
 
 
 {\displaystyle L^{*}}
 
 ("Lstar") is not to be confused with 
 
 
 
 L
 
 
 {\displaystyle L}
 
 as used for luminance. In some color ordering systems such as <a href="/facts/Munsell_color_system/SanJo9rD">Munsell</a>, Lightness is referenced as value.
<a href="/facts/Chiaroscuro/IdAkSPkx">Chiaroscuro</a> and <a href="/facts/Tenebrism/urLDrN7j">tenebrism</a> both take advantage of dramatic contrasts of value to heighten drama in art. Artists may also employ <a href="/facts/Shading/ewcDEfda">shading</a>, subtle manipulation of value.

Lightness open-in-new

Lightness