Data for CIE Illuminants D50 and D65

Below is shown the spectral power distribution of the CIE standard illuminants D50 and D65 at 10nm intervals between 380 and 730nm.

They can be used in the spreadsheet Tristimulus.csv (see the section 'Colour measurement and specification' in the calculation of XYZ tristimulus values and xy chromaticity coordinates.

Wavelength    
(nm) D50 D65
380 24.49 49.98
390 29.87 54.65
400 49.31 82.75
410 56.51 91.49
420 60.03 93.43
430 57.82 86.68
440 74.82 104.86
450 87.25 117.01
460 90.61 117.81
470 91.37 114.86
480 95.11 115.92
490 91.96 108.81
500 95.72 109.35
510 96.61 107.8
520 97.13 104.79
530 102.1 107.69
540 100.75 104.41
550 102.32 104.05
560 100 100
570 97.74 96.33
580 98.92 95.79
590 93.5 88.69
600 97.69 90.01
610 99.27 89.6
620 99.04 87.7
630 95.72 83.29
640 98.86 83.49
650 95.67 80.03
660 98.19 80.21
670 103 82.28
680 99.13 78.28
690 87.38 69.72
700 91.6 71.61
710 92.89 74.35
720 76.85 61.6
730 86.51 69.89

The D65 illuminant is intended to represent average daylight throughout the visible spectrum.

D50 is more commonly used in graphic arts colorimetry, largely because it is closer in colour temperature to typical indoor light sources commonly used by customers to view printed products.

D50 is considered less practical for the white point of colour CRTs (including graphic arts monitors and TVs), since the reduction in power of the blue gun required to achieve a simulation of D50 would result in an unacceptable reduction of overall brightness. Hence D65 is commonly used for this purpose.

Download the data in the form of a spreadsheet