BS EN ISO/CIE 11664-1:2019

What is ISO/CIE 11664-1- CIE standard colorimetric observers about? 

ISO/CIE 11664-1 is a safety standard on colorimetry. 

ISO/CIE 11664-1 specifies colour-matching functions for use in colorimetry.  

Two sets of colour-matching functions are specified: 

Colour-matching functions for the CIE 1931 standard colorimetric observer.  

• This set of colour-matching functions is representative of the colour-matching properties of observers with the normal colour vision for visual field sizes of angular subtense from about 1° to about 4°, for vision at photopic levels of adaptation 

Colour-matching functions for the CIE 1964 standard colorimetric observer.  

• This set of colour-matching functions is representative of the colour-matching properties of observers with a normal colour vision for visual field sizes of angular subtense greater than about 4°, for vision at sufficiently high photopic levels and with spectral power distributions such that no participation of the rod receptors of the retina is to be expected 

Who is ISO/CIE 11664-1- CIE standard colorimetric observers for?  

ISO/CIE 11664-1 on colorimetry is relevant to: 

• Manufacturers of colorimeter 
• Textile industries 
• Food industries 
• Manufacturers of paint 
• Manufacturers of colour spectrometer 

Why should you use ISO/CIE 11664-1- CIE standard colorimetric observers? 

Colours with different spectral compositions can look alike.  

Colorimetry can tell if two metameric colour stimuli look identical. It is difficult to utilise visual colorimeters for this purpose because colour matching between observers with normal colour vision varies. Visual colorimetry takes time. Colorimetry has long used sets of colour-matching functions to compute tristimulus values for colours: equality of tristimulus values for two colours shows that their colour appearances match when seen under the same conditions by an observer who uses the colour-matching functions. 

The use of ISO/CIE 11664-1 sets of colour-matching functions makes the comparison of tristimulus values obtained at various times and locations possible. Overall, ISO/CIE 11664-1 is useful as it aids on a colorimeter that involves the measurement of colour and is used for finding the concentration. 

What’s changed since the last update? 

BS EN ISO/CIE 11664-1:2019 supersedes EN ISO 11664-1:2011. 

BS EN ISO/CIE 11664-1:2019 replaces ISO 11664-1:2007 | CIE S 014-1:2006, of which it constitutes a minor revision, incorporating minor editorial updates.