Lamb's (1995) photopigment template

Template equation

 

 

Equation 2' from Lamb (1995), where S(λ) is the spectral sensitivity, lambda is the wavelength in nm, and λ_max is the wavelength of peak sensitivity in nm. A = 0.880, B = 0.924, C = 1.104, D = 0.655, a = 70, b = 28.5, and c = -14.1.  This equation produces a fixed template shape on a log wavelength, log frequency, or normalized frequency scalein accordance with Mansfield's (1985) proposal.

References

Lamb, T. D. (1995). Photoreceptor spectral sensitivities: common shape in the long-wavelength region. Vision Research, 35, 3083-3091.

Mansfield, R. J. W. (1985). Primate photopigments and cone mechanisms. In A. Fein, & J. S. Levine (Ed.), The visual system New York: Alan R. Liss.