## DeMarco, Pokorny & Smith cone fundamentals

### Data key

**Columns**

*Energy *

- Wavelength (nm)
- log L-cone spectral
sensitivity
- log M-cone spectral
sensitivity
- log S-cone spectral
sensitivity

### Notes

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.

### References

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.