What color is the Sun?
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The Sun's chromaticity (seen from space, without atmospheric
filtering) seems to be about
CIE x y: 0.326 0.338
So, a pixel color of | #fff3ea |
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Here is a comparison with various whitepoints:
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These numbers were calculated using the 1985 Wehrli Standard Extraterrestrial Solar Irradiance Spectrum, the CIE 1931 2 degree Color Matching Functions as modified by Judd (1951) and Vos (1978) , and the sRGB color space primaries, gamma correction, and a D65 whitepoint. Using my blackbody color tool hack.
The choice of white point has a large effect...
0.3259 0.3379 #fff3ea - D65 whitepoint |
0.3259 0.3379 #e0e8ff - D50 whitepoint |
The choice of gamma correction has some small effect... (these are all D65)
#fff3ea - sRGB gamma correction |
#fff2e8 - Rec.709 gamma correction |
The choice of CMFs has some small effect... (these are all Rec.709 (D65))
0.3259 0.3379 #fff2e8 - CIE'31 2 degree CMFs with Judd Vos corrections |
0.3239 0.3338 #fff1eb - CIE'64 10 degree CMFs |
0.3231 0.3327 #fff1ed - CIE'31 2 degree original CMFs |
What colour is the Sun? put a lot more effort into precision than I have done. Better underlying spectrum, better computation. Used CIE 1931 CMFs, and Rec.709.
0.3233 0.3326 #fff1ed - the site, CIE 1931 CMFs, and Rec.709. |
0.3233 0.3326 #fff2ef - the same chromaticity, but converted to pixel color using sRGB instead. |
0.3259 0.3379 #fff3ea - my numbers (for comparison) |
Notes:
Doables:
Explain about whitepoints, D65, and resulting pink/bluishness.
Ie, what does this page mean?
History:
2002-Nov-11 Fixed links broken by CVRL move.
2001-Jun-22 Changed to sRGB.
2001-Jun-08 added D65/D50 contrast; push to ajsh's site.
2001-Jun-05 added CMFs table
2001-Jun-04 on-line