Cesia: Its relation to color in terms of the trichromatic theory

CAIVANO, JOSE LUIS

Die Farbe

Muster-Schmidt Verlag

Lugar: Gottingen; Año: 1996 vol. 42 p. 51 - 63

0014-7680

The word ?cesia? has been coined to refer to the visual sensations aroused bydifferent spatial distributions of light: sensations of transparency, translucency, matte opacity, specularity, gloss, darkness, etc. The trichromatic theory holds that the perception of colors is possible through three kinds of receptors in the retina, sensitive to specific portions of the visible radiation: long wavelength, medium wavelength, and short wavelength; and the science of color has proved that by mixing appropriate amounts of three primary lights all the other colors can be produced. But color sensations are always accompanied by sensations of cesia; the same opaque color may have a glossy or matte aspect, a specular reflectance (mirrorlike appearance) may be colorless or colored, and we can also see color in transparency. Cesia stimuli appear associated with color due to the fact that all the spatial modalities of light transfer may be selective as regards wavelength; if they are nonselective, then we have achromatic or colorless cesias. The explanation arises from the analysis of the possibilities of transmission and reflection (whether they are diffuse or regular), as well as absorption of light, splitting the light stimuli into each primary component.