Color Temperature and the Kelvin Scale

The balance of the amount of color contained in a continuous-spectrum light source that has all the visible wavelengths (red, orange, yellow, green, blue, and violet) in various amounts is measured as

Color Temp Kelvin Scale
4.14 The Kelvin scale is used by photographers to measure the coolness or warmth of light. The bluer (cooler) the light, the higher the Kelvin temperature. This illustration shows the approximate Kelvin temperatures of common photographic light sources. Table 4.3 provides more specific details.

color temperature. Color temperature is expressed on the absolute (Kelvin) scale. The Kelvin scale starts at absolute zero, —273.15 C on the centigrade scale (usually rounded off to —273 C). Absolute zero is the temperature at which all molecular motion theoretically stops. The degree symbol is not used when expressing the color temperature of a light source in Kelvin (K). The Kelvin temperature is determined by adding 273 to the number of degrees centigrade to which a black metal radiator would have to be heated to take on a certain color. A black body is used as a standard gauge since it does not reflect any light falling on it and only emits radiation when heat is applied to it. The Kelvin scale is to the color of light as the ISO scale is to the sensitivity of image sensor (Table 4.3).

0 0


  • Pirkko Haapaniemi
    Why is the kelvin scale absolute?
    7 years ago

Post a comment