DeMarco, Pokorny & Smith cone fundamentals

Data key



  1. Wavelength (nm)
  2. log L-cone spectral sensitivity
  3. log M-cone spectral sensitivity
  4. log S-cone spectral sensitivity



The cone fundamentals at 5-nm steps were obtained from Appendix A of DeMarco, Pokorny & Smith (1992).   Those at 1-nm steps were kindly provided by David Brainard.

These logarithmic M- and L-cone functions differ slightly from the Smith & Pokorny cone fundamentals calculated from the CIE Judd, Vos XYZ CMFs in the 3rd or 4th decimal place < 680 nm. The S-cone function, however, differs by up to ~0.3 log unit markedly from the calculated tables > 600 nm. The authors provided us with this note as to the origin of their S-cone function, for which we thank them:

Here is the history: Some time ago we had the Wyszecki & Stiles 1-nm tabulation of the 1931 CIE CMFs and coordinates scanned into one of our computers. When we needed 1 nm Vos/Judd data we used the Vos equations and the scanned coordinates to derive the coordinates. These yield close but not identical chromaticity coordinates as the Vos tabulation. The discrepancies are small. We typed in the Vos  and computed the CMFs.


DeMarco, P., Pokorny, J., & Smith, V. C. (1992). Full spectrum cone sensitivity functions for X-chromosome linked anomalous trichromats. Journal of the Optical Society of America A, 9, 1465-1476.

Smith, V. C., & Pokorny, J. (1975). Spectral sensitivity of the foveal cone photopigments between 400 and 500 nm. Vision Research, 15, 161-171.