A unit of luminance equal to 1 \/ Π candela per square foot or to the uniform luminance at a perfectly diffusing surface emitting or reflecting light at the rate of one lumen per square foot. A lumen per square foot is a unit of incident light and a footlambert is a unit of emitted or reflected light. For a perfectly reflecting and perfectly diffusing surface, the number of lumens per square foot is equal to the number of footlamberts.

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  • footlambert — (fL, fl or ftL)    a unit of luminance, the brightness of a surface. The footlambert describes the luminance of a surface that emits or reflects one lumen per square foot; it is the luminance of a perfectly reflecting surface under an… …   Dictionary of units of measurement

  • footlambert — noun Date: 1925 a unit of luminance equal to the luminance of a perfectly diffusing surface that emits or reflects one lumen per square foot …   New Collegiate Dictionary

  • footlambert — unit of luminance of a surface emitting one lumen per square foot Units of Measurement …   Phrontistery dictionary

  • footlambert — ˈ ̷ ̷| ̷ ̷ ̷ ̷ noun : a unit of luminance equal to the luminance of a perfectly diffusing surface that emits or reflects one lumen per square foot …   Useful english dictionary

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