Luminance vs. Illuminance

Luminancenoun

The quality of being luminous.

Luminancenoun

The amount of light that passes through, is emitted, or is reflected from a particular area, and falls within a given solid angle.

Luminancenoun

The luminous flux emitted in a given direction divided by the product of the projected area of the source element perpendicular to the direction and the solid angle containing that direction (i.e. luminous intensity divided by unit area), measured in stilbs or apostilbs.

Luminancenoun

the quality of being luminous; emitting or reflecting light;

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 within a given solid angle.

Illuminancenoun

(physics) The luminous flux incident on unit area of a surface; measured in lux or lumens.

Illuminancenoun

the luminous flux incident on a unit area

Illuminance

In photometry, illuminance is the total luminous flux incident on a surface, per unit area. It is a measure of how much the incident light illuminates the surface, wavelength-weighted by the luminosity function to correlate with human brightness perception.