lux
Similar Terms: Lux,lx
lux (symbol; lx) is the >SI unit of illuminance – how brightly a surface is illuminated. One lux is equal to 1 >Lumen per square meter. It is the measure of light intensity, as percieved by the human eye, of the light that illuminates or passes through a surface.
Video and surveillance cameras often include a minimum illuminance level of lux at which the camera will record a satisfactory image. A camera with good low-light capability (night vision camera) will have a lower lux rating. Still cameras do not use such a specification, since longer exposure times can generally be used to make pictures at very low illuminance levels.
Lumens measure >Luminous Flux, or the amount of light produced by a light source, whereas Lux is intended to explain how many >Lumens are needed to illuminate a particular area.
0.0005 lux | Starlight without moon |
0.01 lux | Quarter Moon |
1 lux | Full moon overhead near the equator |
50 lux | Family living room lights |
320 - 500 lux | Office lighting |
10,000 - 25,000 | Full Daylight (not direct sunlight) |