Convert Lux to Phots
Convert Lux (lx) to Phots (ph) instantly and accurately.
Conversion Formula
ph = lx × 0.0001
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.
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 Wholly superseded by lux and kilolux in modern standards. 1 ph = 10⁴ lx.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
| Lux (lx) | Phots (ph) |
|---|---|
| 1 lx | 0.0001 ph |
| 2 lx | 0.0002 ph |
| 5 lx | 0.0005 ph |
| 10 lx | 0.001 ph |
| 25 lx | 0.0025 ph |
| 50 lx | 0.005 ph |
| 100 lx | 0.01 ph |