Definition of halation in English:


Pronunciation /hāˈlāSHən/ /heɪˈleɪʃən/


  • The spreading of light beyond its proper boundaries to form a fog around 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.’
    • ‘The function of pyrazolone derivative in silver halide photographic paper is as a filter to prevent halation and irradiation.’
    • ‘With a regularity attributable to Therrien's use of templates, the forms share a richness and density and, often, a halation at each figure's thin edge.’


Mid 19th century formed irregularly from halo+ -ation.