The photometric equivalent of irradiance. Illuminance is obtained by integrating spectral irradiance weighted by luminous efficiency over the visible spectrum. Compare luminance.

The total amount of light illuminating a point on a surface from all directions above the surface. Illuminance is equivalent to irradiance weighted with the tristimulus response curve of the human eye [..]

The density of incident luminous flux on a surface; illuminance is the standard metric for lighting levels, and is measured in lux (lx) or footcandles (fc).

the incident luminous flux density on a differential element of surface located at a point and oriented in a particular direction, expressed in lumens per unit area. Since the area involved is differential, it is customary to refer to this as illuminance at a point. The unit name depends on the unit of measurement for area: footcandles if square fe [..]

The amount of light falling on a surface expressed in lumens.

(n) the luminous flux incident on a unit area

The total luminous flux incident on a surface per unit area; a measure of how much of the incident light illuminates the surface; measured in lux or foot-candles.

The density of luminous flux on a surface, is measured in footcandles (one lumen per square foot) or lux (one lumen per square meter).

Indicates the light intensity on a surface per unit area. It is measured in footcandles (fc). 1 fc = 1 lumen/square foot.

Density of luminous flux incident on a surface. Unit is footcandle or lux.

The measurement of light in lumens per square metre, the unit of which is the lux.

Illuminance Ev, measured in lux (lx), describes the intensity of the Luminous flux on an illuminated surface A. Illuminance is the Lighting Power per unit area. The formula $1lm/{m^2} = 1lx$ applies.$ [..]

A photometric term that quantifies light incident on a surface or plane. Illuminance is commonly called light level. It is expressed as lumens per square foot (foot-candles), or lumens per square meter (lux).

solar radiation

The luminous flux per unit of area. The derived unit of illuminance in the International System of Units is the LUX.

The amount of light (luminous flux) incident on a surface area. Illuminance is measured in footcandles (lumens/square foot) or lux (lumens/square meter). One footcandle equals 10.76 lux, although for convenience 10 lux commonly is used as the equivalent.

The density of luminous flux incident upon a surface. Illuminance is measured in footcandles (lumens/square foot) or lux (lumens/square meter). One footcandle equals 10.76 lux.

The quantity of light at one point on a surface. It is the quotient of the luminous flux incident on an element of the surface containing the point, and the area of that element. [Unit lux, lx]