The impact of different human eye luminous efficiency functions on color space and lamps color quality parameters

Kowalska Justyna – Warsaw University of Technology, Poland

Nowadays we are under development modern LED light sources but many traditional lamps i.e. incandescent, fluorescent and discharge still in with use in lighting applications. By having so many types of light sources characterized by the emission of radiation with various spectral distributions, lighting designers discover how we can consciously design the lighting application depends on the requirement resulting for example on lighting impact on human.
When designing given lighting, it is always striving to achieve specific parameters describing its quality i.e. illuminance, luminance, UGR and color. Parallel to the revolution in the construction of light sources, also scientific studies on the methods of determining and measuring lighting parameters are carried out. Many kinds of research showed that the basics of the colorimetry which were approved many years ago need to be updated. Contemporary research are focus on designing new colorimetric observers. Some research stays that the luminous efficiency function V(λ) for 2-degree observer which was determined in 1924 by the four examinations related to the direct comparison method and the flicker method is out of date. To improve the system of assessing these light sources quality was introduced 10-degree colorimetric observer. There is also developed the luminous efficiency function V10(𝜆) adapted to this observer. In 1988 CIE introduced another luminous efficiency function VM(λ) for photopic vision which is better matched in the short wavelengths measurements. Likewise, some researches indicated that luminous efficiency functions depend on the age of the observer and lens which increasing the absorption on time and changing the vision.
This means that based on different curves which are describing human eye sensitivity (luminous efficiency functions), is possible to develop different systems for describing the colorimetric parameters of light sources. The aim of this paper is to investigate the impact of different luminous efficiency functions, used as basis for color space, on the chromaticity coordinates for contemporary light sources. The accuracy and sensitivity of each color space will be provided. This research will show which luminous efficacy function could be used as optimal basis of contemporary lamp colorimetric calculation. Additionally the paper will be focus how precisely we can adapt the color system to achieved personal requirements.