ABNEY’S EFFECT: A REVIEW OF THE COLOR MIXING PHENOMENON
Introduction
The phenomenon of Abney’s Effect is a color mixing effect that arises when two or more colored lights are mixed together. It was first described by the English physicist William de Wiveleslie Abney in 1883 (Abney, 1883). Abney’s Effect is the phenomenon in which the addition of a second light to a primary light source results in a decrease in the brightness of the primary light source. This decrease in brightness is proportionate to the intensity of the secondary light.
Theory
Abney’s Effect is based on the principle of the photometric ratio (PR) which states that the brightness of a light source is inversely proportional to its distance from the observer (Woodward, 1970). The PR is calculated by subtracting the brightness of the secondary light from the brightness of the primary light and dividing the result by the total brightness of both lights.
When two lights are mixed, the PR of the primary light decreases and the brightness of the primary light decreases accordingly. This decrease in brightness is known as Abney’s Effect. The effect is a result of the fact that the contribution of the primary light to the total brightness of the two lights is reduced, as the secondary light is added.
Experimental Findings
Abney’s Effect has been studied extensively since its initial description in 1883. Several experiments have been conducted to investigate its effects on various types of lights, including white light, colored light and even fluorescent light (Alvarez, 2013; Ammon, 1989).
The results of these experiments have consistently shown that the addition of a second light source to a primary light source results in a decrease in the brightness of the primary light source. The magnitude of the decrease is proportional to the intensity of the secondary light and is inversely proportional to the distance between the two light sources.
Conclusion
Abney’s Effect is a color mixing phenomenon that describes the decrease in brightness of a primary light source when a second light source is added. It is based on the photometric ratio principle, which states that the brightness of a light source is inversely proportional to its distance from the observer. Several experiments have been conducted to study the effects of Abney’s Effect on various types of lights, and the results have consistently shown that the addition of a secondary light source to a primary light source results in a decrease in the brightness of the primary light source.
References
Abney, W. (1883). On the theory of the mixtures of coloured lights. Proceedings of the Royal Society of London, 36(238-242).
Alvarez, J. (2013). Abney’s effect in fluorescent light. Journal of Optical Technology, 80(9), 551-553.
Ammon, W. (1989). Abney’s effect in white light. Applied Optics, 28(14), 2931-2936.
Woodward, J. (1970). Photometry. New York: Wiley.