Convert Lamberts to Apostilbs
Convert Lamberts (L) to Apostilbs (asb) instantly and accurately.
Conversion Formula
asb = L × 10000
About Lamberts
The lambert (L) equals 10⁴/π cd/m² ≈ 3 183 cd/m², the luminance of a perfect diffuse surface emitting 1 lumen per square centimetre. The CGS practical luminance unit. An incandescent lamp globe at 3 200 K has luminance ~1 L; a clear sky is ~0.94 L. Superseded by cd/m² in SI photometry. 1 L = 10⁴/π cd/m².
About Apostilbs
The apostilb (asb) equals 1/π cd/m² ≈ 0.3183 cd/m², defined as the luminance of a perfectly diffuse Lambertian surface with an exitance of 1 lm/m². Introduced by the CIE in 1940 and used in European photometry standards and retinal illuminance calculations. 1 asb = 1/π cd/m² ≈ 0.3183 cd/m².
Quick Reference Table
| Lamberts (L) | Apostilbs (asb) |
|---|---|
| 1 L | 10000 asb |
| 2 L | 20000 asb |
| 5 L | 50000 asb |
| 10 L | 100000 asb |
| 25 L | 250000 asb |
| 50 L | 500000 asb |
| 100 L | 1000000 asb |