How many phots are in one lux?

One lux equals 0.0001 ph. The formula is ph = lx × 0.0001.

How do I convert lux to phots?

Multiply the value in lux by 0.0001. For example, 100 × 0.0001 = 0.01 — so 100 lx = 0.01 ph.

Pair · linear · factor 0.0001

lux to phots

lxph

Active unit

lux · ≈ 100 lx (base)

All units

3 results

Click to activate · Ctrl-click to set target

lxlux100

How we calculated this

Target:

Frequently asked questions

An emerald lamp casting a cone of light onto a desktop overlaid with an inverse-square-law grid, against a cosmic nebula in violet and magenta

Illuminance

Lumens are not lux — why a desk needs 500 lux

A light-bulb box shouts “800 lumens,” “1600 lumens” — and it feels obvious that a bigger number means a brighter room. It is a trap. Whether you see well is decided by the lux: how much of that emitted light actually lands on your desk. This is the story of illuminance — the inverse-square law, why a full moon gives a quarter of a lux yet still lets you walk at night, and why the office standard is exactly 500 lux.

13 min