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lambert

A unit of luminance, 1920s - 1950s, in the centimeter-gram-second system of units. A surface emitting 1 lumen per square centimeter has a luminance of 1 lambert. Symbol, L.

In SI units, one lambert is exactly 10,000/pi (or approximately 3,183.099) candelas per square meter.

The lambert is named for J. H. Lambert (1728 – 1777), an early German photometrician.

According to the current national standard in the United States¹, the lambert is not to be used.

1. IEEE/ASTM SI 10™-2002.
American National Standard for Use of the International System of Units (SI): The Modern Metric System.
New York: IEEE, 30 December 2002.

See Section 3.3.3.