Convert Candelas per square foot to Foot-lamberts
Convert Candelas per square foot (cd/ft²) to Foot-lamberts (fL) instantly and accurately.
Conversion Formula
fL = cd/ft² × 3.141592654
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 Foot-lamberts
The foot-lambert (fL) equals 1/(π×0.09290304) cd/m² ≈ 3.426 cd/m², the luminance of a perfect diffuse surface emitting 1 lumen per square foot. The SMPTE standard for cinema screen luminance is 14 fL (≈48 cd/m²); home projectors are rated 10-35 fL. Still standard in US cinema and theatre engineering. 1 fL = 1/(π×ft²) cd/m².
Quick Reference Table
| Candelas per square foot (cd/ft²) | Foot-lamberts (fL) |
|---|---|
| 1 cd/ft² | 3.14159 fL |
| 2 cd/ft² | 6.28319 fL |
| 5 cd/ft² | 15.708 fL |
| 10 cd/ft² | 31.4159 fL |
| 25 cd/ft² | 78.5398 fL |
| 50 cd/ft² | 157.08 fL |
| 100 cd/ft² | 314.159 fL |