Convert Foot-candles to Phots
Convert Foot-candles (fc) to Phots (ph) instantly and accurately.
Conversion Formula
ph = fc × 0.001076391042
About Foot-candles
The foot-candle (fc) equals 1 lm/ft² ≈ 10.764 lx. Standard in North American lighting design: IESNA recommends 30-50 fc for general offices, 50-100 fc for retail displays, 12-16 fc for cinema screens. Still the dominant unit in the US, Canada and some other countries. 1 fc = 1/0.09290304 lx.
About Phots
The phot (ph) equals 1 lm/cm² = 10 000 lx. The CGS-photometric unit of illuminance. Pre-SI optics texts express daylight in phots: full tropical sunshine is ~10 ph (100 klx); overcast sky ~0.1-0.2 ph. Wholly superseded by lux and kilolux in modern standards. 1 ph = 10⁴ lx.
Quick Reference Table
| Foot-candles (fc) | Phots (ph) |
|---|---|
| 1 fc | 0.00107639 ph |
| 2 fc | 0.00215278 ph |
| 5 fc | 0.00538196 ph |
| 10 fc | 0.0107639 ph |
| 25 fc | 0.0269098 ph |
| 50 fc | 0.0538196 ph |
| 100 fc | 0.107639 ph |