Foot Candles 

 An example of a foot-candles readout on a film light meter: you need 100 foot-candles at 100 asa to get a 2.8 aperture.

An example of a foot-candles readout on a film light meter: you need 100 foot-candles at 100 asa to get a 2.8 aperture.

 
 

Light meters for film measure foot candles

They measure intensity of light equivalent to lux, a unit of measure of the intensity of light falling on to a surface equal to one lumen per square foot. It was originally defined with reference to a standardized candle burning at one foot from a given surface.

More on foot-candles here