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Luminance Converter

Free Luminance Converter for other units. Enter a value to see equivalent measurements across systems. Free to use with no signup required.

Reviewed by Manoj Kumar, Mathematics Educator

Reviewed by Manoj Kumar, Mathematics Educator

Formula

Converted Luminance = Value x (From Factor / To Factor)

Each luminance unit has a conversion factor to candela per square meter (cd/m2) as the base unit. One nit equals one cd/m2. One foot-lambert equals 3.42626 cd/m2. One stilb (cd/cm2) equals 10,000 cd/m2. One lambert equals approximately 3183.1 cd/m2. The apostilb relates to the lambert by a factor of pi.

Worked Examples

Example 1: Converting Display Brightness to Foot-Lamberts

Problem:A monitor has a brightness of 500 cd/m2 (nits). Convert to foot-lamberts.

Solution:cd/m2 = 500 (same as nits)\nFoot-lamberts = 500 / 3.42626 = 145.95 fL

Result:500 nits = 145.95 foot-lamberts

Example 2: Converting Stilb to Nits

Problem:Convert 0.05 stilb (cd/cm2) to nits (cd/m2).

Solution:cd/m2 = stilb x 10,000\ncd/m2 = 0.05 x 10,000 = 500 nits\nFoot-lamberts = 500 / 3.42626 = 145.95 fL

Result:0.05 stilb = 500 nits

Frequently Asked Questions

What is luminance and how does it differ from illuminance?

Luminance measures the brightness of a surface as perceived by the human eye, expressed in candela per square meter (cd/m2 or nits). It describes the light emitted or reflected from a surface in a given direction. Illuminance, measured in lux, describes the amount of light falling onto a surface. Think of luminance as how bright something looks and illuminance as how much light hits it. A white wall and a black wall under the same illuminance have different luminance because they reflect different amounts of light.

What luminance levels correspond to real-world scenarios?

Clear sky luminance is approximately 8000 cd/m2. Direct sunlight on white paper reaches about 30,000 cd/m2. A candle flame is roughly 7000 cd/m2. The full moon surface has a luminance of about 2500 cd/m2 as seen from Earth. A typical office computer monitor set to comfortable brightness is 120-200 cd/m2. Street lighting produces about 1-2 cd/m2 on road surfaces. The human eye can perceive luminance ranging from about 0.000001 cd/m2 (starlight) to over 100,000 cd/m2 (sunlit snow).

References

Reviewed by Manoj Kumar, Mathematics Educator · Editorial policy