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Lumen Output vs. Foot Candles

Foot-Candles vs. Lumens -

A "foot-candle" is a unit of measure for quantifying the intensity of light falling on an object. A "lumen" is a unit of measure for quantifying the amount of light energy emitted by a light source. In other words, foot-candles measure the brightness of the light at the illuminated object, while lumens measure the power of the light radiated by the light source.

Both foot-candles and lumens are units measurements of electromagnetic radiation detectable by the human eye. Foot-candles are used to measure "luminance," the density of light energy reaching a reference surface at a given distance from one or more light sources. Lumens are used to measure "luminous flux," the amount and rate of light energy radiated by a particular light source.

A foot-candle is based on the English system of measurements. A foot-candle equals 1 lumen per square foot. The international standard (SI) counterpart of the foot-candle is the "lux." A lux equals 1 lumen per square meter. The equation used to convert foot-candles to lux is: 1 foot-candle = 10.76 lux.