Color rendering index: Difference between revisions

Revision as of 02:54, 27 September 2006

Revision as of 04:44, 3 October 2006

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{{Merge-date|September 2006|color rendering capacity|date=September 2006}}

The '''color rendering index (CRI)''' (sometimes called Color Rendition Index), is a measure of the ability of a light source to reproduce the colors of various objects being lit by the source. It is a method devised by the [[International Commission on Illumination]] (CIE). The best possible rendition of colors is specified by a CRI of one hundred, while the very poorest rendition is specified by a CRI of zero. For a source like a low-pressure [[sodium vapor lamp]], which is monochromatic, the CRI is nearly zero, but for a source like an [[incandescent light bulb]], which emits essentially [[black body]] radiation, it is nearly a hundred. The CRI is measured by comparing the color rendering of the test source to that of a "perfect" source which is generally a black body radiator, except for sources with [[color temperature]]s above 5000K, in which case a simulated daylight (e.g. [[D65]]) is used. For example, a standard "cool white" [[fluorescent lamp]] will have a CRI near 62. Newer "triphosphor" fluorescents often claim a CRI of 80 to 85.