Judd-modified CIE Photopic luminosity curve (1951)

Data key

Columns

Energy

Linear

1. Wavelength (nm)
2. Photopic luminous efficiency, V(λ)
   

Logarithmic

1. Wavelength (nm)
2. log Photopic luminous efficiency, V(λ)
   

Quantal

Logarithmic

1. Wavelength (nm)
2. log Photopic luminous efficiency, V(λ)
   

Notes

From Wyszecki and Stiles (1982), Table 1(5.5.2).

    The standard photopic luminosity function, which was based on a curious combination of luminosity data from several sources and obtained by several methods (Gibson & Tyndall, 1923; CIE, 1926), seriously underestimates sensitivity in the violet part of the spectrum. In 1951, Judd proposed this revised version of V(λ) in an attempt to overcome this problem.  Judd's corrections, which were confined to wavelengths below 460 nm, produced a "standard observer" with an artificially high macular pigment density.

References

CIE (1926). Commission Internationale de l'Eclairage Proceedings, 1924. Cambridge: Cambridge University Press.

Gibson, K. S., & Tyndall, E. P. T. (1923). Visibility of radiant energy. Scientific Papers of the Bureau of Standards, 19, 131-191.

Judd, D. B. (1951). Report of U.S. Secretariat Committee on Colorimetry and Artificial Daylight. In Proceedings of the Twelfth Session of the CIE, Stockholm (vol. 1, pp. 11). Paris: Bureau Central de la CIE.

Wyszecki, G., & Stiles, W. S. (1982). Color Science: concepts and methods, quantitative data and formulae. (2nd ed.). New York: Wiley.