Convert Phots to Lumens per square yard
Convert Phots (ph) to Lumens per square yard (lm/yd²) instantly and accurately.
Conversion Formula
lm/yd² = ph × 8361.2736
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 Wholly superseded by lux and kilolux in modern standards. 1 ph = 10⁴ lx.
About Lumens per square yard
The lumen per square yard (lm/yd²) equals 1/0.83612736 lx ≈ 1.196 lx. Used occasionally in UK outdoor area lighting specifications alongside foot-candles. A 3 lx minimum car-park standard equals ~2.5 lm/yd²; a 100 lx sports-field requirement ~84 lm/yd². 1 lm/yd² = 1/0.83612736 lx.
Quick Reference Table
| Phots (ph) | Lumens per square yard (lm/yd²) |
|---|---|
| 1 ph | 8361.27 lm/yd² |
| 2 ph | 16722.5 lm/yd² |
| 5 ph | 41806.4 lm/yd² |
| 10 ph | 83612.7 lm/yd² |
| 25 ph | 209032 lm/yd² |
| 50 ph | 418064 lm/yd² |
| 100 ph | 836127 lm/yd² |