As a standard light is called the standardized spectral distribution curves characteristic radiator.
Radiation distributions, which are the black body nearly identical are mapped as color temperatures. These correspond to the emitted radiation from the Planckian radiator at the appropriate temperature.
In the ISO standard ISO 3664, the criteria for standard light are defined
Some selected standard light indicating the color temperature and the color value components:
- Illuminant A: relative radiation distribution of the Planckian ( black ) radiator with 2856 Kelvin
- D65: distribution of radiation with a color temperature of 6504 Kelvin (roughly equivalent to a gray overcast sky ). Also standardized are D50 (preferably in the printing industry ), D55 and D75. The "D" incipient standard light types include UV components, which are not visible to humans, but when working with fluorescent surfaces ( such as for certain types of paper ) are important. This standard light types correspond with the natural sunlight UV component of sunlight.
- Standard light types F1 ... F12: so-called department store light for fluorescent lamps with different UV components.