Convert Stilbs to Foot-lamberts

Convert Stilbs (sb) to Foot-lamberts (fL) instantly and accurately.

Conversion Formula

fL = sb × 2918.63508

About Stilbs

The stilb (sb) equals 1 cd/cm² = 10⁴ cd/m². The CGS luminance unit. A candle flame has luminance ~0.5-0.6 sb; a frosted incandescent bulb ~10 sb; a xenon short-arc lamp up to 170 000 sb. Named from the Greek στίλβω (to glitter). Found in pre-1970 photometry texts. 1 sb = 10⁴ 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

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