- Mathematical concepts
- >
- Quantity
- >
- Units of measurement
- >
- Units of luminous flux

- Quantity
- >
- Units of measurement
- >
- Units of photometry
- >
- Units of luminous flux

Lumen (unit)

The lumen (symbol: lm) is the unit of luminous flux, a measure of the total quantity of visible light emitted by a source per unit of time, in the International System of Units (SI). Luminous flux dif

Rayleigh (unit)

The rayleigh is a unit of photon flux, used to measure faint light emitted in the sky, such as airglow and auroras. It was first proposed in 1956 by , Franklin E. Roach, and . It is named for Robert S

© 2023 Useful Links.