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Standard method of assessing the spectral quality of daylight simulators for visual appraisal and measurement of colour

ISO/CIE 23603:2024
Division 1

This ISO/CIE International Standard was prepared by the International Commission on Illumination (CIE) in cooperation with Technical Committee ISO/TC 274, Light and lighting.
This first edition of ISO/CIE 23603 cancels and replaces ISO 23603:2005, which has been technically revised. Prior reference numbers of the publication (CIE S 012:2004, ISO 23603:2005) have been replaced by ISO/CIE 23603:2024.
The purpose of the assessment method described in this publication is to quantify the suitability of the spectral irradiance distribution of a practical daylight simulator of CIE daylight illuminant D55, D75 or CIE standard daylight illuminants D50 and D65 for the visual appraisal and measurement of colours of fluorescent or non-fluorescent specimens.

The basis for the assessment is the special metamerism index for change in illuminant, using pairs of virtual (rather than real) specimens specified by their reflecting and fluorescing properties. The pairs of specimens are metameric matches under the CIE daylight illuminant, when evaluated with the CIE 1964 standard colorimetric observer. The method described in this publication quantifies the mismatch when the pairs of virtual specimens are illuminated by the daylight simulator under test and evaluated by the same standard colorimetric observer.

A visible range metamerism index is derived to quantify the suitability of the simulator for the visible wavelength range. An ultraviolet range metamerism index is derived using a different set of virtual metameric pairs, each pair having a fluorescent and a non-fluorescent specimen which spectrally match for the CIE daylight illuminant and CIE standard colorimetric observer. The non-fluorescent specimen in each pair is specified by its spectral radiance factor. The fluorescent specimen in each pair is specified by its spectral reflected radiance factor, relative spectral distribution of radiance due to fluorescence and spectral external radiant efficiency of the fluorescent specimen. The ultraviolet range metamerism index quantifies the mismatch due to fluorescence that results from the use of the daylight simulator and the CIE 1964 standard colorimetric observer.

The publication is written in English. It consists of 19 pages and is readily available from the CIE Webshop or from the National Committees of the CIE. The price of this publication is EUR 135,- (Members of a National Committee of the CIE receive a 66,7 % discount on this price – please approach your NC for information on accessing this discount).