Color temperature
Description
The temperature (in degrees Kelvin) a blackbody radiator would need to have in order to match the color of a light source. A black body radiator uniformly emits an envelope of radiation. The color of its emission continually changes as its temperature increases. A low color temperature (1000 K) indicates a dull red light, a medium temperature (3000 K) gives an orange-red glow while a high color temperature (5000 K) indicates a bright blue-white light. Thus, the color temperature indicates the perceived 'warmth' (red) or 'coolness' (blue) of a light. The color temperature does not indicate the amount of heat given off by the light.
Some light sources and their color temperatures (CT) are:
- Candle flame (1800-2900 K);
- High pressure sodium (2100 K);
- Incandescent 40W (2650 K) and 100W (2900 K);
- Tungsten halogen 50W (3200 K);
- Warm white fluorescence (4000 K);
- Metal halide (3900 K);
- Cool white fluorescence (4200 K);
- Electronic flash, D50 (5000K)
- Bright midday sun, summer (6000 K);
- Hazy sky (7000-8000K);
- Heavily overcast sky (10000K);
- Skylight filter (12000-18000 K)
Synonyms and Related Terms
CT; chromaticity; correlated color temperature (CCT); colour temperature (Br.); Farbtemperatur (Deut.); température de couleur (Fr.); temperatura di colore (It.); kleurtemperatuur (Ned.); temperatura barwowa (Pol.)
Resources and Citations
- Walter C. McCrone, John Gustave Delly, The Particle Atlas, W. McCrone Associates, Chicago, IV, 1972
- Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996
- Book and Paper Group, Paper Conservation Catalog, AIC, 1984, 1989
- Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
- Thomas B. Brill, Light Its Interaction with Art and Antiquities, Plenum Press, New York City, 1980
- Olympus Microscopy: www.olympusmicro.com/primer/photomicrography/colortemperature.html - source for most color temperature values
- Wikipedia: http://en.wikipedia.org/wiki/Color_temperature (Accessed Sept. 20, 2005)