Action spectrum for the production fo previtamin-D3 in human skin,
CIE Techincal Report TC 6-54, Commission Internationale
del'Eclairage, 2006.
Values below 260 nm and beyond 315 nm were interpolated by CIE using
a spline fit.
Wavelength, nm
     Relative response
252  0.036
253  0.039
254  0.043
255  0.047
256  0.051
257  0.056
258  0.061
259  0.066
260  0.075
261  0.084
262  0.093
263  0.102
264  0.112
265  0.122
266  0.133
267  0.146
268  0.160
269  0.177
270  0.195
271  0.216
272  0.238
273  0.263
274  0.289
275  0.317
276  0.346
277  0.376
278  0.408
279  0.440
280  0.474
281  0.543
282  0.583
283  0.617
284  0.652
285  0.689
286  0.725
287  0.763
288  0.805
289  0.842
290  0.878
291  0.903
292  0.928
293  0.952
294  0.976
295  0.983
296  0.990
297  0.996
298  1.000
299  0.977
300  0.951
301  0.917
302  0.878
303  0.771
304  0.701
305  0.634
306  0.566
307  0.488
308  0.395
309  0.306
310  0.220
311  0.156
312  0.119
313  0.083
314  0.049
315  0.034
316  0.020
317  1.41E-02
318  9.76E-03
319  6.52E-03
320  4.36E-03
321  2.92E-03
322  1.95E-03
323  1.31E-03
324  8.73E-04
325  5.84E-04
326  3.90E-04
327  2.61E-04
328  1.75E-04
329  1.17E-04
330  7.80E-05