Cesia (visual appearance)

These interactions of light with matter are perceived with a greater or lesser degree of gloss (from a mirror to a matte surface, as the extremes), more or less transparent, translucent or opaque, at different levels of darkness (according to the light-dark axis).

The variable of diffusivity, which involves different degrees of light scattering, from zero to maximum, and the appearances in-between the two extremes, is related to the concept of distinctness of image (DOI).

Jannello died in 1985 without developing the concept in depth (beyond the fact that it refers to qualities or visual appearances such as transparency, translucency, gloss, opacity, etc.

[6][7] Subsequently, the concept of cesia was also taken up and expanded by other authors, who applied it to different fields: Green-Armytage (1993, 2017),[8][9] Lozano (2006),[10] Giglio (2015),[11] Jofré (2017),[12] to mention just a few.

A detailed chronology of publications, as well as background information, course syllabi, videos on the subject, pictures of different scales of cesia, and other related items, can be found here:

Possible spatial distributions of light incident on a surface.
Five basic cesias: black, matte, specular, translucent, and transparent.
Diagram of the order system for cesias.
A scale of cesia: from transparent to opaque (variation of permeability), by mixing clear water and milk.
A scale of cesias from specular to matte (variation of diffusivity), by progressive tarnished of a mirror.
A scale of cesias from transparent to black (variation of darkness), using neutral density filters.
Gradual variation of cesia from translucent to transparent (change in diffusivity): Frosted glass at decreasing distances in front of an object.