Abney effect

An illustration of the Abney effect. As white is added to red, it shifts slightly towards magenta; green shifts towards cyan, and blue shifts towards violet. The RGB primaries on a typical display are not monochromatic, making the effect weaker than in the usual experimental setup.

The Abney effect or the purity-on-hue effect is the perceived hue shift that occurs when white light is added to a monochromatic light source.[1][2]

The addition of white light will cause a desaturation of the monochromatic source, as perceived by the human observer. However, a less intuitive effect of the perceived white light addition is the change in the apparent hue. This hue shift is physiological rather than physical in nature.

This variance of hue as a result of the addition of white light was first described by the English chemist and physicist Sir William de Wiveleslie Abney in 1909, although the date is commonly reported as 1910. A white light source can be created by the combination of red, blue, and green light. Abney demonstrated that the cause of the apparent change in hue was the red and green light that comprised this light source, and that the blue light component had no contribution to the Abney effect.[3]

  1. ^ Pridmore, R. “Effect of purity on hue (Abney effect) in various conditions.” Color Research and Application. 32.1 (2007): 25–39.
  2. ^ Pridmore, Ralph W.; Melgosa, Manuel (10 April 2015). "All Effects of Psychophysical Variables on Color Attributes: A Classification System". PLOS ONE. 10 (4): e0119024. doi:10.1371/journal.pone.0119024. PMC 4393130. PMID 25859845.
  3. ^ W. de W. Abney. “On the Change in Hue of Spectrum Colours by Dilution with White Light.” Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character. 83.560 (1909): 120–127.