Convert Phots to Microlux

Convert Phots (ph) to Microlux (µlx) instantly and accurately.

Phots (ph)
Microlux (µlx)

Conversion Formula

µlx = ph × 10000000000

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 Wholly superseded by lux and kilolux in modern standards. 1 ph = 10⁴ lx.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 Microlux

The microlux (µlx) equals 10⁻⁶ lx. Natural night illuminance: a moonless overcast sky ~100 µlx; scattered starlight ~200-300 µlx; crescent moon ~10-50 µlx. Used in night-vision equipment sensitivity specifications and observatory site-quality assessments. 1 µlx = 10⁻⁶ lx.

Quick Reference Table

Phots (ph)Microlux (µlx)
1 ph1 × 1010 µlx
2 ph2 × 1010 µlx
5 ph5 × 1010 µlx
10 ph1 × 1011 µlx
25 ph2.5 × 1011 µlx
50 ph5 × 1011 µlx
100 ph1 × 1012 µlx

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