Convert Apostilbs to Lamberts
Convert Apostilbs (asb) to Lamberts (L) instantly and accurately.
Conversion Formula
L = asb × 0.0001
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.
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 An incandescent lamp globe at 3 200 K has luminance ~1 L; a clear sky is ~0.94 L. Superseded by cd/m² in SI photometry. 1 L = 10⁴/π cd/m².
Quick Reference Table
| Apostilbs (asb) | Lamberts (L) |
|---|---|
| 1 asb | 0.0001 L |
| 2 asb | 0.0002 L |
| 5 asb | 0.0005 L |
| 10 asb | 0.001 L |
| 25 asb | 0.0025 L |
| 50 asb | 0.005 L |
| 100 asb | 0.01 L |