Definitions for "Halation"
An appearance as of a halo of light, surrounding the edges of dark objects in a photographic picture.
A spreading or reflection of light, a halolike effect that occurs in reverse reading letters, where the background is significantly darker than the illuminated letters.
A term originally used in photography to denote the process by which the image in a developed emulsion is spread beyond the bounds of the incident light. Is used to describe the spreading of light from one order to the next in an échelle spectrogram.
An effect caused by extreme contrast between the illuminated and unilluminated portions of a sign and which affects the ability of the eye to focus on that sign. The effect is also dependent on color.