Lambert (unit)

The lambert (symbol L) is an unit of luminance named for Johann Heinrich Lambert (1728 - 1777), a German mathematician, physicist and astronomer. A related unit of luminance, the foot-lambert, is used in the lighting, cinema and flight simulation industries. The SI unit is the candela per square metre (cd/m²).

Definition

1 lambert (L) = ${\frac {1}{\pi }}$ candela per square centimetre (0.3183 cd/cm²) or ${\frac {10^{4}}{\pi }}$ cd m^-2

Reference

• "Lighting Design Glossary: Luminance" at Schorsch Lighting Design Knowledgebase