Convert Apostilbs to Candelas per square inch
Convert Apostilbs (asb) to Candelas per square inch (cd/in²) instantly and accurately.
Conversion Formula
cd/in² = asb × 0.0002053608062
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 Candelas per square inch
The candela per square inch (cd/in²) equals 1/0.00064516 cd/m² ≈ 1 550 cd/m². Used in US LED and CRT datasheets when citing luminance of small emitter areas. A high-brightness packaged LED chip in a focussed-beam configuration can reach 1-20 cd/in². 1 cd/in² = 1/(0.0254²) cd/m².
Quick Reference Table
| Apostilbs (asb) | Candelas per square inch (cd/in²) |
|---|---|
| 1 asb | 0.000205361 cd/in² |
| 2 asb | 0.000410722 cd/in² |
| 5 asb | 0.0010268 cd/in² |
| 10 asb | 0.00205361 cd/in² |
| 25 asb | 0.00513402 cd/in² |
| 50 asb | 0.010268 cd/in² |
| 100 asb | 0.0205361 cd/in² |