Abney effect
The Abney effect describes the perceived shift in hue that occurs when white light is added to light from a monochromatic light source . It was first described by the English chemist and photographer Sir William de Wiveleslie Abney in 1909.
description
When white light is added to a monochromatic (ie “single color”) light source, the light source is “ desaturated ”. This is perceived by the human eye as a change in color. This change occurs to different degrees for different colors. For example, a white light source is created by combining red light, blue light, and green light. Sir Abney showed that the cause of the apparent change in color is the red and green light that comprise the light source. The blue light component of the white hue had no effect on the Abney effect.
Psychological aspect
The visual system consists of a chromatic neural channel and an achromatic neural channel. The chromatic channel consists of a red-green and a blue-yellow sub-channel and is responsible for color recognition. The achromatic channel is responsible for luminance , also known as white-black detection. The hue or saturation is determined by the activity in the achromatic channel. The achromatic has a faster response time than the chromatic neural channel under most conditions. The functions of the channels are task-dependent.
For example, two different skills from the channels can function as one. When a colored stimulus is summed with a white one, both the chromatic and achromatic channels are activated. Here, the achromatic channel will have a somewhat slower response time, as it has to adapt to the different luminance. Despite this delayed response, the speed of the achromatic channel will still be faster than the speed and response of the color channel.
Under these conditions of summed pulses, the magnitude of the signal emitted by the achromatic channel will be stronger than the signal of the chromatic channel. Coupling the faster response with the higher amplitude signal from the achromatic channel means that the response time is likely to be dependent on the luminance and saturation values of the stimuli.
The usual explanations for color vision describe the difference in the perception of the hue as an elementary sensation. However, there are no specific physiological limitations or theories regarding the response to any particular hue. Based on the Abney effect, no color tone plays a special role; every color tone can change due to different lighting. It is still unclear whether the Abney effect is a more coincidental effect in color perception or whether it is important for color perception in the eye.
Trivia
- In 1995 a patent was granted for a color printer to compensate for the Abney effect.
- The effect plays a role in the cockpits of combat aircraft . For example, when white light hits the screens, the colors become desaturated. This makes the image more difficult to see on the screens.
Individual evidence
- ^ W. de W. Abney: On the Change in Hue of Spectrum Colors by Dilution with White Light . In: Proc. R. Soc. Lond . A, 1909, p. 120–127 , doi : 10.1098 / rspa.1909.0085 ( Proc. R. Soc. Lond. A - online [PDF; accessed November 4, 2014]).
- ^ TD Kulp, K. Fuld: The prediction of hue and saturation for non-spectral lights . In: Visual Research . tape 35 , no. 21 , 1995, p. 2967-2983 , doi : 10.1016 / 0042-6989 (95) 00049-6 ( Science Direct [accessed November 4, 2014]).
- ↑ United States Patent and Trademark Office. Retrieved October 8, 2019 .
- ^ Heino Widdel: Color in Electronic Displays . Ed .: Springer publishing. Springer, 1992, ISBN 978-1-4757-9754-1 , pp. 21-23 .