Foot-lambert calculator

     To calculate from screen dimensions, click here

Luminance conversion

     4 cd/m2 (candela per square meter)
     0.3716 cd/sq.ft. (candela per square foot)
     1.1675 ftL (foot-lambert)
     5 EV (Exposure Value)

Screen luminance: EV5

-5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
starlight to dim ambient lightmoon eclipse to night home interiorneon lights to landscape after sunsetbright light to weak sunbright daylight to direct sunlight

Explanation

A foot-lambert or footlambert (ftL, sometimes fl or ft-L) is a unit of luminance. For screens that are projected upon (like cinema, home cinema), it quantifies how much light is reflected (to the center of the room). This depends on the amount of light produced (lumens), the size of the screen and the screen gain.

Examples

References