A foot-candle (sometimes foot candle; abbreviated fc, lm/ft2, or sometimes ft-c) is a non-SI unit of illuminance or light intensity.
[1] Nearly all of the world uses the corresponding SI derived unit lux, defined as one lumen per square meter.
The foot-candle is defined as the illuminance of the inside surface of a one-foot-radius sphere with a point source of one candela at its center.
Alternatively, it can be defined as the illuminance of one lumen on a one-square foot surface with a uniform distribution.
In the motion picture cinematography field in the US, incident light meters are used to measure the number of foot-candles present, which are used to calculate the intensity of motion picture lights, allowing cinematographers to set up proper lighting-contrast ratios when filming.