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To: SeeSac
[Me] I'm referring to the color in Kelvins, not to temperature in degrees Kelvin. They're different.

[You, being a PITA] They are the same.

Not.

See below, found online. (Which you could have done.)

Color Temperature (Kelvins) and Color Rendition Index (CRI)

The color of light is determined by its wavelength. The two ratings that are commonly used to describe the color properties of lamps are color temperature and color rendition (CRI). Color temperature is the color appearance of the light produced by a bulb and the color appearance of the bulb itself. It is measured on a Kelvin scale (K). A bulb with a low color temperature will have a "warm" appearance (red, orange, or yellow). Conversely, a bulb with a high color temperature will have a "cool" appearance (blue or blue-white). Color rendition is a measure of how the lamp influences the color appearance of the objects that are being illuminated. It represents the ability of a lamp to render color accurately and to show color shade variations more clearly. High color rendition allows us to see objects, as we would expect them to appear under natural sunlight. Color rendition is measured via a complex process on the Color Rendition Index scale ranging in value from 0 to 100.

To put it in slightly different terms, the color temperature of light refers to the temperature to which one would have to heat a "black body" source to produce light of similar spectral characteristics. Low color temperature implies warmer (more yellow/red) light while high color temperature implies a colder (more blue) light. The standard unit for color temperature is Kelvin (k). (The Kelvin unit is the basis of all temperature measurement, starting with 0 k at the absolute zero temperature. The "size" of one Kelvin is the same as that of one degree Celsius, and is defined as the fraction 1/273.16 of the thermodynamic temperature of the triple point of water, which positions 0° Celsius at 273.16 k.)

It shouldn't be forgotten that a color temperature value, though expressed as a single number, doesn't describe a simple property. In reality, it only summarizes the spectral properties of a light source. Two light sources with the same light color can differ widely in quality, e.g. when one of them has a continuous spectrum, while the other just emits light in a few narrow bands of the spectrum. Some of the qualitative aspects of such a spectrum can be summarized by means of its color rendering index (CRI). Therefore the higher the CRI, the higher the “quality” of the light produced. CRI is measured on a scale from 0 to 100. A 100 CRI light bulb does not exist. Our HID bulbs range from 60 to 90 CRI depending on the bulb's manufactor and the salt mixture inside the bulb.

Blogsource:

http://tinyurl.com/63x6bxm

Black-body radiation is not what we are discussing in these illumination sources. See the discussion at link about color rendition indices, and the fact that common light sources do not usually have full spectra.

80 posted on 01/23/2011 7:44:12 PM PST by lentulusgracchus (Concealed carry is a pro-life position.)
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To: lentulusgracchus
The blogger's source for the quote cited above:

http://tinyurl.com/4t3wta5

81 posted on 01/23/2011 7:52:40 PM PST by lentulusgracchus (Concealed carry is a pro-life position.)
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To: lentulusgracchus

If you say so.


82 posted on 01/24/2011 5:57:19 AM PST by SeeSac
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To: lentulusgracchus
[Me] I'm referring to the color in Kelvins, not to temperature in degrees Kelvin. They're different.

Color temperature is a characteristic of visible light that has important applications in lighting, photography, videography, publishing, manufacturing, astrophysics, and other fields. The color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of comparable hue to that of the light source. Color temperature is conventionally stated in the unit of absolute temperature, the kelvin, having the unit symbol K.

http://en.wikipedia.org/wiki/Color_temperature

85 posted on 01/24/2011 6:54:34 AM PST by SeeSac
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