luminous flux
total amount of light energy flowing out of a light source per unit of time
Key facts
- Common symbols
- Φ v
- Si unit
- lumen
- In si base units
- cd ⋅ sr
- Dimension
- J {\displaystyle {\mathsf {J}}}
via Wikipedia infobox
Article
In photometry, luminous flux or luminous power is the measure of the perceived power of light. It differs from radiant flux, the measure of the total power of electromagnetic radiation (including infrared, ultraviolet, and visible light), in that luminous flux is adjusted to reflect the varying sensitivity of the human eye to different wavelengths of light.
Photopic (black line) and scotopic (green line) luminosity functions. The photopic includes the CIE 1931 standard (solid), the Judd–Vos 1978 modified data (dashed), and the Sharpe, Stockman, Jagla & Jägle 2005 data (dotted). The horizontal axis is wavelength in nm. Integrating sphere used for measuring the luminous flux of a light source