# 17-23-003

colour stimulus function

φλ(λ)

function describing the spectral distribution of the colour stimulus

Note 1 to entry: The colour stimulus function is generated by the spectral distribution of a radiometric quantity, such as radiance or radiant flux.

Note 2 to entry: For object colours the colour stimulus function, φλ(λ), is equal to the product of the relative spectral distribution, S(λ), and either the spectral reflectance, ρ(λ), or the spectral radiance factor, β(λ), or the spectral transmittance, τ(λ), depending on the application.

Note 3 to entry: This entry was numbered 845-03-03 in IEC 60050-845:1987.

Note 4 to entry: This entry was numbered 17-230 in CIE S 017:2011.

Publication date: 2020-12