Lux

The lux (abbreviated lx) is the SI derived unit of illuminance or illumination. It is equal to one lumen per square metre.

sunlight on an average day ranges from 32,000 to 100,000 lux
TV studios are lit at about 1,000 lux
a bright office has about 400 lux of illumination
moonlight represents about 1 lux
starlight measures a mere 0.00005 lux

Lux is also the name of a commune in the C�te-d'Or d�partement in France.