The Bezold–Brücke shift or luminance-on-hue effect
is a change in
hue
In color theory, hue is one of the main properties (called color appearance parameters) of a color, defined technically in the CIECAM02 model as "the degree to which a stimulus can be described as similar to or different from stimuli that ...
perception as light intensity changes. As intensity increases,
spectral colors shift more towards blue (if below 500 nm) or yellow (if above 500 nm). At lower intensities, the red/green axis dominates. This means that reds become more yellow with increasing brightness. Light may change in the perceived hue as its brightness changes, despite the fact that it retains a constant spectral composition. It was discovered by
Wilhelm von Bezold
Johann Friedrich Wilhelm von Bezold (June 21, 1837 – February 17, 1907) was a German physicist and meteorologist born in Munich, Kingdom of Bavaria. He is best known for discovering the Bezold effect and the Bezold–Brücke shift.
Bezold ...
and M.E. Brücke.
The shift in the hue of the colors that occur as the intensity of the corresponding energy change is materially increased, except in some cases like the change for certain invariable hues (approximating the psychologically primary hues). Both Bezold & Brücke worked on the Bezold-Brücke effect and gave important contributions in the field of optical illusions.
This effect is a problem for simple
HSV-style
color model
A color model is an abstract mathematical model describing the way colors can be represented as tuples of numbers, typically as three or four values or color components. When this model is associated with a precise description of how the compon ...
s, which treat hue and intensity as independent parameters. In contrast,
color appearance models try to factor in this effect.
The shift in the hue is also accompanied by the changes in the perceived saturation. As the brightness of the color stimuli increases, their color strength also increases to a maximum point and then decreases again; in such a way that it is still wavelength specific. This can, to an extent, be considered as an inverse of the ''
Helmholtz-Kohlrausch effect''. In the case of the Helmholtz Kohlrausch effect, the partially desaturated stimulus is seen to be brighter than fully saturated or achromatic stimulus.
See also
*
Opponent process
The opponent process is a color theory that states that the human visual system interprets information about color by processing signals from photoreceptor cells in an antagonistic manner. The opponent-process theory suggests that there are th ...
*
Purkinje shift
*
Abney effect
The Abney effect or the purity-on-hue effect describes the perceived hue shift that occurs when white light is added to a monochromatic light source.
The addition of white light will cause a desaturation of the monochromatic source, as perceive ...
Bibliography
* W. von Bezold: ''Die Farbenlehre in Hinblick auf Kunst und Kunstgewerbe''. Braunschweig 1874.
* "Über das Gesetz der Farbenmischung und die physiologischen Grundfarben", ''Annalen der Physiologischen Chemie'', 1873, 226: 221–247.
*M. E. Brücke, “Über einige Empfindungen im Gebiet der Sehnerven,” Sitz. Ber. d. K. K. Akad. d. Wissensch. Math. Nat. Wiss. 1878, 77:39–71.
References
Color appearance phenomena
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