Problem

# Lightness

Other Names:
Illumination
Brightness
Delicacy
Weightlessness
Slightness
Airiness
Flippancy
Flightiness
Frivolousness
Levity
Silliness
Cheerfulness
Gaeity
Brilliance
Nature:

Lightness is a visual perception of the luminance ( L ) {\displaystyle (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 standard observer. While luminance is a linear measurement of light, lightness is a linear prediction of the human perception of that light.

This is 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 CIECAM02 or L ∗ {\displaystyle L^{*}} as used in CIELAB and CIELUV. L ∗ {\displaystyle L^{*}} ("Lstar") is not to be confused with L {\displaystyle L} as used for luminance. In some color ordering systems such as Munsell, Lightness is referenced as value. Some color models such as HSV also use value as an alternate term for lightness.

Chiaroscuro and Tenebrism both take advantage of dramatic contrasts of value to heighten drama in art. Artists may also employ shading, subtle manipulation of value.