C.I.E. Photopic Luminous Efficiency Function:
--------------------------------------------
The 1931 Y function is a linear combination of red, green, and blue cone
responses, with negligible weight to blue and heavier weight to green and
red. The X function is a linear combination of all three, with more red
than blue, and the green's coefficient being negative. The Z function is
close to just the blue cone response.
Chromaticity coordinates (lower case x, y, and z) for a given wavelength
are X, Y, and Z divided by the sum of all three. For non-monochromatic
light, add up the X, Y, and Z for each wavelength, then divide these three
totals by the sum of all three.
In 1988 CIE updated the Photopic Luminous Efficiency Function because the
1931 function did not sufficiently weight the higher blue response of
young people.
******** 1988 C.I.E. Photopic Luminous Efficiency Function ********
Wavelength +0 nm +1 nm +2 nm +3 nm +4 nm
----------------------------------------------------------------------------
380 nm 0.0002000 0.0002280 0.0002610 0.0002990 0.0003440
385 nm 0.0003960 0.0004550 0.0005250 0.0006040 0.0006960
390 nm 0.0008000 0.0009160 0.0010500 0.0012000 0.0013600
395 nm 0.0015500 0.0017500 0.0018800 0.0022300 0.0025000
400 nm 0.0028000 0.0031200 0.0034600 0.0038300 0.0042300
405 nm 0.0046600 0.0051200 0.0056200 0.0061700 0.0067600
410 nm 0.0074000 0.0081500 0.0089600 0.0098300 0.0108000
415 nm 0.0118000 0.0128000 0.0140000 0.0151000 0.0163000
420 nm 0.0175000 0.0186000 0.0196000 0.0207000 0.0217000
425 nm 0.0227000 0.0236000 0.0246000 0.0255000 0.0264000
430 nm 0.0273000 0.0283000 0.0294000 0.0304000 0.0315000
435 nm 0.0326000 0.0337000 0.0347000 0.0358000 0.0369000
440 nm 0.0379000 0.0388000 0.0398000 0.0406000 0.0415000
445 nm 0.0424000 0.0433000 0.0441000 0.0450000 0.0459000
450 nm 0.0468000 0.0477000 0.0487000 0.0498000 0.0509000
455 nm 0.0521000 0.0534000 0.0549000 0.0564000 0.0581000
460 nm 0.0600000 0.0626000 0.0653000 0.0680000 0.0709000
465 nm 0.0739000 0.0770000 0.0803000 0.0837000 0.0872000
470 nm 0.0910000 0.0949000 0.0990000 0.1040000 0.1080000
475 nm 0.1130000 0.1180000 0.1230000 0.1280000 0.1330000
480 nm 0.1390000 0.1450000 0.1500000 0.1560000 0.1630000
485 nm 0.1690000 0.1760000 0.1840000 0.1910000 0.1990000
490 nm 0.2080000 0.2170000 0.2270000 0.2370000 0.2470000
495 nm 0.2590000 0.2700000 0.2822900 0.2950500 0.3085700
500 nm 0.3230000 0.3384000 0.3546800 0.3716900 0.3892800
505 nm 0.4073000 0.4256200 0.4443000 0.4633900 0.4829300
510 nm 0.5030000 0.5235600 0.5445100 0.5656900 0.5869600
515 nm 0.6082000 0.6293400 0.6503000 0.6708700 0.6908400
520 nm 0.7100000 0.7281800 0.7454600 0.7619600 0.7778300
525 nm 0.7932000 0.8081100 0.8224900 0.8363000 0.8494900
530 nm 0.8620000 0.8738100 0.8849600 0.8954900 0.9054400
535 nm 0.9148500 0.9237300 0.9320900 0.9399200 0.9472200
540 nm 0.9540000 0.9602500 0.9660000 0.9712600 0.9760200
545 nm 0.9803000 0.9840900 0.9874800 0.9903100 0.9928100
550 nm 0.9949500 0.9967100 0.9980900 0.9991100 0.9997400
555 nm 1.0000000 0.9998500 0.9993000 0.9983200 0.9968900
560 nm 0.9950000 0.9926000 0.9897400 0.9864400 0.9827200
565 nm 0.9786000 0.9740800 0.9691700 0.9638500 0.9581300
570 nm 0.9520000 0.9454500 0.9384900 0.9311600 0.9234500
575 nm 0.9154000 0.9070000 0.8982700 0.8892000 0.8797800
580 nm 0.8700000 0.8598600 0.8493900 0.8386200 0.8275800
585 nm 0.8163000 0.8047900 0.7930800 0.7811900 0.7691500
590 nm 0.7570000 0.7447500 0.7324200 0.7200000 0.7074900
595 nm 0.6949000 0.6822100 0.6694700 0.6567400 0.6438400
600 nm 0.6310000 0.6181500 0.6053100 0.5924700 0.5796300
605 nm 0.5668000 0.5539600 0.5411300 0.5283500 0.5156300
610 nm 0.5030000 0.4904600 0.4780300 0.4656700 0.4534000
615 nm 0.4412000 0.4290800 0.4170300 0.4050300 0.3930300
620 nm 0.3810000 0.3689100 0.3568200 0.3447700 0.3328100
625 nm 0.3200000 0.3093300 0.2978500 0.2865900 0.2756200
630 nm 0.2650000 0.2547600 0.2448800 0.2353300 0.2260500
635 nm 0.2170000 0.2081600 0.1995400 0.1911500 0.1829700
640 nm 0.1750000 0.1672200 0.1596400 0.1522700 0.1451200
645 nm 0.1382000 0.1315000 0.1250200 0.1187700 0.1127600
650 nm 0.1070000 0.1014700 0.0962000 0.0911000 0.0863000
655 nm 0.0816000 0.0771000 0.0728000 0.0687000 0.0648000
660 nm 0.0610000 0.0574000 0.0540000 0.0507000 0.0475000
665 nm 0.0446000 0.0418000 0.0391000 0.0366000 0.0342000
670 nm 0.0320000 0.0300000 0.0281000 0.0263000 0.0247000
675 nm 0.0232000 0.0218000 0.0205000 0.0193000 0.0181000
680 nm 0.0170000 0.0159000 0.0148000 0.0138000 0.0128000
685 nm 0.0119000 0.0111000 0.0103000 0.0095300 0.0088500
690 nm 0.0082100 0.0076200 0.0070900 0.0065900 0.0061400
695 nm 0.0057200 0.0053400 0.0050000 0.0046800 0.0043800
700 nm 0.0041000 0.0038400 0.0035900 0.0033500 0.0031300
705 nm 0.0029300 0.0027400 0.0025600 0.0023900 0.0022400
710 nm 0.0020900 0.0019500 0.0018200 0.0017000 0.0015900
715 nm 0.0014800 0.0013800 0.0012900 0.0012000 0.0011200
720 nm 0.0010500 0.0009770 0.0009110 0.0008500 0.0007930
725 nm 0.0007400 0.0006900 0.0006430 0.0005990 0.0005580
730 nm 0.0005200 0.0004840 0.0004500 0.0004180 0.0003890
735 nm 0.0003610 0.0003350 0.0003110 0.0002890 0.0002680
740 nm 0.0002490 0.0002310 0.0002150 0.0001990 0.0001850
745 nm 0.0001720 0.0001510 0.0001490 0.0001380 0.0001290
750 nm 0.0001200 0.0001120 0.0001040 0.0000973 0.0000908
755 nm 0.0000848 0.0000791 0.0000739 0.0000689 0.0000643
760 nm 0.0000600 0.0000560 0.0000522 0.0000487 0.0000454
765 nm 0.0000424 0.0000396 0.0000369 0.0000345 0.0000321
770 nm 0.0000300 0.0000280 0.0000261 0.0000244 0.0000227
775 nm 0.0000212 0.0000198 0.0000185 0.0000172 0.0000161
780 nm 0.0000150
