Convert Phots to Lux
Convert Phots (ph) to Lux (lx) instantly and accurately.
Conversion Formula
lx = ph × 10000
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 Wholly superseded by lux and kilolux in modern standards. 1 ph = 10⁴ lx.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 Lux
The lux (lx) is the SI coherent unit of illuminance, equal to 1 lm/m². Civil twilight outdoors: ~10 lx; dimly lit corridor: ~50 lx; typical office (EN 12464): 300-500 lx; operating theatre: ~1 000 lx. The most widely used illuminance unit in lighting standards worldwide. 1 lx = 1 lm/m².
Quick Reference Table
| Phots (ph) | Lux (lx) |
|---|---|
| 1 ph | 10000 lx |
| 2 ph | 20000 lx |
| 5 ph | 50000 lx |
| 10 ph | 100000 lx |
| 25 ph | 250000 lx |
| 50 ph | 500000 lx |
| 100 ph | 1000000 lx |