Is there a difference between a light source and an illuminant?

 

Yes, there is!

 

By the term “light source” we describe any object that emits “light” (relative energy distribution in the visible spectrum app. 380 - 750nm). The quality and energy of this light is not described and can vary; sunlight for example will vary in its appearance during the day and time of year as well as with the weather. Thus, a “light source” is not reliably mathematically described or technically reproducible and not suited for colorimetric characterization.

 

To have a reliable, consisting description of a light source, the CIE (Commission Internationale de l’Eclairage) evaluated and agreed upon binding standards for different types of light sources. These reproducible light sources are named “illuminants” and represent the mathematical tables of values (relative energy versus wavelength) used for colorimetric calculations.

 

Among these are descriptions for types of daylight, fluorescent lamps or special light sources.

 

3nh offered full light sources portable spectrophotometer, NS810/NS800/NS820/NS808 models. NH310 portable colorimeter and NR60CP precision colorimeter also can customize full light sources.