Luminance units describing luminous intensity per projected area. Illuminance, luminous flux and luminous intensity are separate quantities.
All factors come from the central conversion registry.
| Unit | Symbol | System | Definition |
|---|---|---|---|
| Nit | nt | SI-derived photometry | 1 nt = 1 cd/m² |
| Foot-lambert | fL | US customary photometry | 1 fL ≈ 3.4262590996 cd/m² |
| Stilb | sb | CGS | 1 sb = 10,000 cd/m² |
| Lambert | L | CGS | 1 L = 10,000/π cd/m² |
| Apostilb | asb | Legacy photometry | 1 asb = 1/π cd/m² |
Luminance units describing luminous intensity per projected area. Illuminance, luminous flux and luminous intensity are separate quantities.
The interactive calculator, reference table and indexed pair pages all read from the same conversion registry, so unit definitions and formulas stay synchronized.