Convert Candelas per square foot to Apostilbs
Convert Candelas per square foot (cd/ft²) to Apostilbs (asb) instantly and accurately.
Conversion Formula
asb = cd/ft² × 33.81582189
About Candelas per square foot
The candela per square foot (cd/ft²) equals 1/0.09290304 cd/m² ≈ 10.76 cd/m². Used in US lighting engineering; an illuminated office ceiling panel has luminance ~4-8 cd/ft². The ANSI ergonomic limit for computer workstation background sources is ~340 cd/ft². 1 cd/ft² = 1/0.09290304 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
| Candelas per square foot (cd/ft²) | Apostilbs (asb) |
|---|---|
| 1 cd/ft² | 33.8158 asb |
| 2 cd/ft² | 67.6316 asb |
| 5 cd/ft² | 169.079 asb |
| 10 cd/ft² | 338.158 asb |
| 25 cd/ft² | 845.396 asb |
| 50 cd/ft² | 1690.79 asb |
| 100 cd/ft² | 3381.58 asb |