Convert Lumens per square yard to Phots
Convert Lumens per square yard (lm/yd²) to Phots (ph) instantly and accurately.
Conversion Formula
ph = lm/yd² × 0.0001195990046
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.
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 Wholly superseded by lux and kilolux in modern standards. 1 ph = 10⁴ lx.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
| Lumens per square yard (lm/yd²) | Phots (ph) |
|---|---|
| 1 lm/yd² | 0.000119599 ph |
| 2 lm/yd² | 0.000239198 ph |
| 5 lm/yd² | 0.000597995 ph |
| 10 lm/yd² | 0.00119599 ph |
| 25 lm/yd² | 0.00298998 ph |
| 50 lm/yd² | 0.00597995 ph |
| 100 lm/yd² | 0.0119599 ph |