Derivation of the 1964 colorimetric standards

Although the CIE states that the 1931 2° [ x (λ), y (λ), z (λ)] standard observer characteristics and those of the 1964 10° [ x 10 (λ), y 10 (λ), z 10 (λ)] standard observer were derived from experimental data in the same way, there are differences. One discrepancy is a difference of 6 nm in the tangent wavelength of the ( Y )( Z ) line on the chromaticity chart, with a corresponding change in the minimum wavelength of x 10 . The reason for this is investigated and the two systems are considered. © 1998 John Wiley & Sons, Inc. Col Res Appl, 23, 221–225, 1998