Lux

Lux is a standard unit of light measurement. It is used in specifications of security cameras to indicate how much light is necessary to operate the camera. The lower the lux level, the lower ambient light the camera can operate in.

Technically, one Lux is equal to one lumen per square meter. See hyperphysics,phy-astr,gsu,edu/hbase/vision/areance,html for a formal physics definition.

At a minimum, cameras used only in daylight or where good lighting is available, should have a rating of 2 Lux or more.

Cameras with a Lux rating of 0.2 Lux or less are considered low-light cameras.

It is not possible to get good color definition at low light levels, so low light cameras are either monochrome or use electronics to switch to monochrome under low light conditions.

Low light or night cameras are often infrared sensitive. These cameras work with ambient infrared light or are used in conjunction with an infrared illuminator.

Approximate Lux	Situation
< 0.001	Starlight - overcast night
0.001 - 0.01	Starlight - clear night
0.01 - 0.1	Overcast Night
0.1 - 1	Moonlight
1 - 100	Dusk / Twilight
100 - 10,000	Overcast Day
10,000 - 1,000,000	Bright Sunlight