noun
- A unit of luminance equal to one lumen per square foot, used to measure the brightness of a surface or light source.
Usage: technical; physics/optics; largely replaced by the candela per square meter (cd/m²) in modern usage
Examples
- The display screen was calibrated to emit 100 footlamberts of brightness.
- Engineers measured the footlambert output of the projection system to ensure adequate visibility.
- The old lighting standard specified a minimum of 50 footlamberts for the work surface.
- Modern monitors are typically rated in candelas per square meter rather than footlamberts.