WHAT is the
Color Rendering Capacity ?
HOW to calculate the Color Rendering Capacity ?
WHAT is the Color Rendering Capacity ?
* The color rendering capacity
is one more measure of the color rendering quality of light,
--devised for dealing with the concern of whether a given kind of light sources is capable of
--rendering a great number of widely different colors.
* In physics, the color rendering capacity of a light source concerns the volume in color space
--occupied by the set of the points that represent all the object colors producible
--under illumination of the spectral power distribution of the given l;ight source with one unit
* In calculation, the color rendering capacity of a light source is a figure proportional to the
--volume of the color solid corresponding to the spectral power distribution of
--the given light source. Specifically the figure equals the volume of the color solid corresponding
--to the spectral power distribution of the given light source divided by the volume of the
--color solid corresponding to equal energy spectrum. Obviously the color rendering capacity
--of equal energy spectrum is 1.00. The color rendering capacity of an incandescent lamp is 0.60.
* In lighting application, the higher the color rendering capacity of a certain kind of light sources,
--the wider the range of the colors that can be vividly rendered by that kind of light sources under
--the same light level,or, in everyday language, the larger the number of the colors that can be
--vividly rendered by that kind of light sources under the same light level.
The color rendering capcity vs the CIE color rendering index
* Both are
developed for assessing the color rendering quality of light
--Each of the two deals with one different aspect of the color rendering quality.
* The color rendering capacity focuses on the issue of how wide a range of colors can be
--vividly rendered by a given light source. That is an issue of the effectiveness of color rendering.
--(Xu He, Color Rendering Capacity of Illumination, Amazon, 2010)
* The CIE color rendering index addresses the subject of how closely the color appearances of a
--group of color samples under a given light source resemble those under a reference illuminant.
--That is a subject of the accuracy of color rendering.
--( CIE Publication 13.2, Method of measuring and specifying colour rendering properties of
--light sources, 1974)
* If one is interested in which kind of light sources can make the color appearance of a scene
--look more like that under daylighting, then the CIE color rendering index is the right measure
--to be used and most likely to be helpful.
* If one wants to know whether a given light source is capable of vividly rendering a great
--number of widely fifferent colors and making a scene look colorful, then the color rendering
--capacity is the right measure to be chosen and most likely to be helpful.
How to calculate the Color Rendering Capacity