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
250 lx	0.025 ph
500 lx	0.05 ph
1000 lx	0.1 ph

Convert Lux to Phots

Convert lux to phots (lx to ph) with our instant calculator. 1 lx = 0.0001 ph. Includes exact formula and reference tables.

How to Convert Lux to Phots (lx to ph)

1 Lux (lx) is equal to 0.0001 Phots (ph). Divide the lux value by 10000

Quick Answer 1 lx = 0.0001 ph

Formula ph = lx / 10000

Inverse Factor 1 ph = 10000 lx

Unit Definitions & Metrology Context

The SI unit of illuminance is the lux (lx), which equals one lumen per square meter (1 lx = 1 lm/m²). It quantifies the intensity of light falling on a given surface.

About Lux (lx): Lux (lx) is a unit in the Illuminance measurement category. It is widely used in si standard illuminance (1 lumen/m²). The lux (lx) serves as the primary reference base unit for the illuminance domain.

About Phots (ph): Phot (ph) is a unit in the Illuminance measurement category. It is widely used in cgs optical standard (10,000 lux / 1 lm/cm²). Relative to the illuminance base unit, 1 ph equals 10000 Lux (lx).

Need to convert in the opposite direction? Visit our Convert Phots to Lux (ph to lx) calculator (1 ph = 10000 lx).

Step-by-Step Worked Examples (lx to ph)

Convert 5 Lux to Phots: Applying the formula (ph = lx / 10000): starting with 5 lx, divide the lux value by 10000 to get 0.0005 ph.
Convert 10 Lux to Phots: Applying the formula (ph = lx / 10000): starting with 10 lx, divide the lux value by 10000 to get 0.001 ph.
Convert 50 Lux to Phots: Applying the formula (ph = lx / 10000): starting with 50 lx, divide the lux value by 10000 to get 0.005 ph.

Popular Illuminance Conversions

Lux ⇄ Foot-candle

Multiply lux by ~0.092903 to calculate illuminance in foot-candles (or divide lux by 10.7639).

Foot-candle ⇄ Lux

Multiply foot-candles by ~10.7639 to convert to lux (1 fc ≈ 10.764 lx).

Kilolux ⇄ Lux

1 kilolux equals exactly 1,000 lux (typical overcast daylight is 1–10 klx).

Phot ⇄ Lux

1 phot equals exactly 10,000 lux (1 lumen per square centimeter).

Frequently Asked Questions

Verified answers and formulas for converting lux to phots.

How many phots are in 1 lux?

There are 0.0001 phots (ph) in 1 lux (lx). Conversely, 1 phot equals 10000 lux.

How do you convert lux to phots?

To convert lux (lx) to phots (ph), use the formula: ph = lx / 10000. Divide the lux value by 10000. For example, 10 lx equals 0.001 ph.

How do I convert back from phots to lux?

To convert in the reverse direction from phots (ph) to lux (lx), use the inverse formula: lx = ph × 10000. Multiply the phot value by 10000 (1 ph = 10000 lx).

What is the difference between lux (lx) and phot (ph)?

Both lux and phot measure illuminance. Lux (lx) is a unit in the Illuminance measurement category. It is widely used in si standard illuminance (1 lumen/m²). The lux (lx) serves as the primary reference base unit for the illuminance domain. Phot (ph) is a unit in the Illuminance measurement category. It is widely used in cgs optical standard (10,000 lux / 1 lm/cm²). Relative to the illuminance base unit, 1 ph equals 10000 Lux (lx).

How do you convert foot-candles (fc) to lux (lx)?

Multiply the foot-candle value by 10.7639. For example, standard office lighting of 50 fc equals approximately 538.2 lux (50 × 10.7639 ≈ 538 lx).