The total radiance is the integral of the distribution over all positive values, and that is invariant for a given temperature under any parameterization. Additionally, for a given temperature the radiance consisting of all photons between two wavelengths must be the same regardless of which distribution you use. That is to say, integrating the wavelength distribution from λ λ 1 to λ λ 2 will result in the same value as integrating the frequency distribution between the two frequencies that correspond to λ λ 1 and λ λ 2 , namely from c / λ λ 2 to c / λ λ 1 . However, the distribution shape depends on the parameterization, and for a different parameterization the distribution will typically have a different peak density, as these calculations demonstrate.