Intensity is a broad term that usually refers to luminous intensity, which is the amount of luminous flux emitted by a source in a particular solid angle, measured in candelas. In radiometry, it means radiant intensity. Technicians and stagehands often use the word loosely to describe the perceived brightness of a fixture or the percentage level of a dimmer channel.
Bring the intensity on channel four down to fifty percent so it stops blowing out the camera.
Do not mix it up with
- Luminance: Intensity is the light emitted in a specific direction, while luminance is the light emitted or reflected per unit area of a surface.
Related terms
Luminous intensity
How much light a source sends out in one specific direction, measured in candelas.
Candela
The unit for how much light a source throws in one direction, and the SI base unit behind lumens and lux.
Radiometry
Measurement of optical radiation in physical energy units such as watts, without weighting for human vision.