Lux to Phot

1 Lux equals 0.0001 Phot using exact lux-based illuminance definitions.

Direct Answer

1 Lux equals 0.0001 Phot

This conversion uses exact lux-based illuminance definitions.

For 10 Lux, the result equals 0.001 Phot.

Converter Calculator

0.0001 Phot (ph)

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Explanation

Formula: Phot = Lux × 0.0001. Why: phot is tied exactly to lux through the square-centimeter to square-meter area relationship, so the route normalizes through lux before applying the target unit.

Lux (lx): the SI derived unit of illuminance, equal to one lumen incident on one square meter of surface area.

Phot (ph): a CGS illuminance unit equal to one lumen per square centimeter, which is exactly 10,000 lux.

This route is useful when comparing phot-based CGS illuminance values against modern lux-based references in laboratory, optical, and legacy technical material.

This conversion is purely multiplicative because both units reduce through lux using fixed illuminance definitions with no offset.

Method & Reference

  • Method basis: exact conversion formula shown in Direct Answer.
  • Applied factor: 1 Lux = 0.0001 Phot (using exact lux-based illuminance definitions).
  • Consistency rule: calculator output and table values use the same constants and rounding policy.

Common Conversion Values

Lux (lx)Phot (ph)
1 0.0001
10 0.001
50 0.005
100 0.01
300 0.03
500 0.05
1,000 0.1
10,000 1

Frequently Asked Questions

What is 1 lux in phot?

1 Lux equals 0.0001 Phot on this page.

Does this Lux to Phot page use the exact lux relationship for phot?

Yes. Phot routes use the exact relationship 1 phot = 10,000 lux through one lux normalization path, so CGS and modern lighting references stay consistent across the page.

When would I convert lux to phot?

This route is useful when comparing phot-based CGS illuminance values against modern lux-based references in laboratory, optical, and legacy technical material.

How do I reverse Lux to Phot?

Use the mirror Phot to Lux route; it applies the inverse relationship with the same illuminance assumptions.