1 Scope
This CIE Standard specifies methods of calculating the tristimulus values of colour
stimuli for which the spectral distributions are provided. These colour stimuli may
be produced by self-luminous light sources or by reflecting or transmitting objects.
The Standard requires that the colour stimulus function be tabulated at measurement
intervals of 5 nm or less in a wavelength range of at least 380 nm to 780 nm. Extrapolation
methods are suggested for cases where the measured wavelength range is less than 380 nm
to 780 nm.
The standard method is defined as summation at 1 nm intervals over the wavelength
range from 360 nm to 830 nm. Alternative abridged methods are defined for larger intervals
(up to 5 nm) and shorter ranges (down to 380 nm to 780 nm). The alternative methods
are to be used only when appropriate and when the user has reviewed the impact on
the final results.
The Standard may be used in conjunction with the CIE 1931 standard colorimetric observer
or the CIE 1964 standard colorimetric observer.