Image:Cones and Photopic smj2.png

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Cones_and_Photopic_smj2.png‎ (356 × 265 pixels, file size: 7 KB, MIME type: image/png)

[edit] Summary

I made this in matlab (and screen captured it as a quick hack), from quantal data at http://www.cvrl.org/database/text/cones/smj2.htm. The black curve is a linear combination of the long and medium cone responses, and represents the photopic luminosity function. Probably other data sets are less lumpy.

Here's the code:

 % http://www.cvrl.org/database/text/cones/smj2.htm

 conelogQdata = [ ...
   390,   -3.0536,  -3.1218,  -1.8575
   395,   -2.6325,  -2.6873,  -1.4547
   400,   -2.3323,  -2.3991,  -1.1582
   405,   -2.0247,  -2.0729,  -0.8393
   410,   -1.7957,  -1.8257,  -0.6069
   415,   -1.6600,  -1.6650,  -0.4141
   420,   -1.5187,  -1.4822,  -0.2550
   425,   -1.4501,  -1.3680,  -0.1432
   430,   -1.3922,  -1.2659,  -0.0835
   435,   -1.3344,  -1.1736,  -0.0378
   440,   -1.2716,  -1.0844,  -0.0103
   445,   -1.2323,  -1.0269,   0.0000
   450,   -1.1974,  -0.9771,  -0.0408
   455,   -1.1460,  -0.9159,  -0.0921
   460,   -1.0725,  -0.8364,  -0.1178
   465,   -0.9894,  -0.7564,  -0.1928
   470,   -0.9006,  -0.6754,  -0.2351
   475,   -0.8224,  -0.6067,  -0.3359
   480,   -0.7603,  -0.5561,  -0.4687
   485,   -0.7056,  -0.5121,  -0.6037
   490,   -0.6324,  -0.4519,  -0.7369
   495,   -0.5422,  -0.3785,  -0.8579
   500,   -0.4505,  -0.3036,  -0.9869
   505,   -0.3575,  -0.2249,  -1.1168
   510,   -0.2766,  -0.1596,  -1.2672
   515,   -0.2050,  -0.1025,  -1.4381
   520,   -0.1440,  -0.0545,  -1.6145
   525,   -0.0984,  -0.0239,  -1.8070
   530,   -0.0645,  -0.0056,  -1.9975
   535,   -0.0434,   0.0000,  -2.1850
   540,   -0.0312,  -0.0036,  -2.3691
   545,   -0.0177,  -0.0066,  -2.5498
   550,   -0.0065,  -0.0139,  -2.7273
   555,   -0.0023,  -0.0318,  -2.9016
   560,   -0.0053,  -0.0597,  -3.0728
   565,   -0.0050,  -0.0874,  -3.2411
   570,    0.0000,  -0.1132,  -3.4064
   575,   -0.0048,  -0.1560,  -3.5689
   580,   -0.0171,  -0.2128,  -3.7286
   585,   -0.0289,  -0.2694,  -3.8856
   590,   -0.0444,  -0.3343,  -4.0400
   595,   -0.0668,  -0.4155,  -4.1919
   600,   -0.0954,  -0.5065,  -4.3412
   605,   -0.1301,  -0.6048,  -4.4880
   610,   -0.1725,  -0.7153,  -4.6326
   615,   -0.2231,  -0.8382,  -4.7747
   620,   -0.2824,  -0.9675,  -4.9146
   625,   -0.3510,  -1.1030,  -5.0523
   630,   -0.4299,  -1.2484,  -5.1879
   635,   -0.5179,  -1.4024,  -5.3213
   640,   -0.6131,  -1.5588,  -5.4527
   645,   -0.7169,  -1.7152,  -5.5821
   650,   -0.8318,  -1.8748,  -5.7096
   655,   -0.9581,  -2.0376,  -5.8350
   660,   -1.0928,  -2.2038,  -5.9586
   665,   -1.2337,  -2.3715,  -6.0804
   670,   -1.3788,  -2.5374,  -6.2004
   675,   -1.5257,  -2.6991,  -6.3186
   680,   -1.6747,  -2.8577,  -6.4351
   685,   -1.8271,  -3.0183,  -6.5500
   690,   -1.9841,  -3.1809,  -6.6632
   695,   -2.1495,  -3.3474,  -6.7747
   700,   -2.3213,  -3.5155,  -6.8848
   705,   -2.4916,  -3.6812,  -6.9932
   710,   -2.6521,  -3.8405,  -7.1003
   715,   -2.8055,  -3.9935,  -7.2057
   720,   -2.9676,  -4.1481,  -7.3098
   725,   -3.1275,  -4.3010,  -7.4125
   730,   -3.2852,  -4.4521,  -7.5137
   ];

 lambda = conelogQdata(:,1);
 responses = 10.^conelogQdata(:,[2 3 4]);
 photopic = responses(:,[1 2]) * [0.68273; 0.35235];

 figure(1); hold off
 plot(lambda, responses)
 hold on
 plot(lambda, photopic, 'k')
 hold off
 axis([380 720 0 1.05])

[edit] Licensing

I, the copyright holder of this work, hereby release it into the public domain. This applies worldwide. In case this is not legally possible, I grant any entity the right to use this work for any purpose, without any conditions, unless such conditions are required by law.

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