halation
/həˈleɪʃ(ə)n
/noun [mass noun]
The spreading of light beyond its proper boundaries to form a fog round the edges of a bright image in a photograph or on a television screen.If these are indeed the causes of halation, then I see no reason why halation should not also take place in a paper emulsion....
- The Sabatier edge effects, which appear as white lines between areas of distinctly different densities, were proven (by Stevens and Norrish in 1937) to be the result of diffusion halation.
- This gives normal contrast range with highlight halation.
Origin
Mid 19th century: formed irregularly from halo + -ation.