Phot to Watt per Square Centimeter (at 555 nm) Conversion

Convert between Phot and Watt per Square Centimeter (at 555 nm) quickly and accurately.

From Phot

To Watt per Square Centimeter (at 555 nm)

W/cm² (at 555 nm)

How to Convert Phot to Watt per Square Centimeter (at 555 nm)

Conversion Formula

1 ph = 0.001 W/cm² (at 555 nm)

1 W/cm² (at 555 nm) = 683 ph

Example

Convert 15 ph to W/cm² (at 555 nm):

15 ph = 15 × 0.001 W/cm² (at 555 nm) = 0.022 W/cm² (at 555 nm)

Unit Information

Learn about the illumination units you're converting between

Phot

Definition

The Phot is a CGS unit of illuminance equal to 10,000 lux, representing one lumen per square centimeter. It is a larger unit used for measuring very high levels of illumination, particularly in scientific and technical applications where high light intensities are common.

History/Origin

Developed as part of the CGS system of units, where the phot provided a convenient way to express high illumination values. It was widely used in scientific literature and technical applications before the adoption of SI units became standard practice.

Current Use

Primarily found in older scientific literature and specialized technical applications. It provides a practical scale for measuring very bright light sources and is still occasionally referenced in photometric research and historical technical documents.

Multiplier

10000

Offset

Watt per Square Centimeter (at 555 nm)

W/cm² (at 555 nm)

Definition

The Watt per Square Centimeter (at 555 nm) is a unit of spectral irradiance that can be converted to illuminance at the peak sensitivity wavelength of the human eye. It represents the radiant power per unit area at 555 nm, weighted by the luminous efficacy of radiation.

History/Origin

Developed for converting between radiometric and photometric quantities at the peak sensitivity wavelength of human vision. It provides a bridge between physical light measurements and perceived brightness, using the luminous efficacy of 683 lumens per watt at 555 nm.

Current Use

Used in optical engineering, laser technology, and display characterization where the relationship between radiant power and perceived brightness is important. It allows for precise conversion from physical measurements to photometric quantities for monochromatic light sources.

Multiplier

6830000

Offset