halation

Noun

1. The action of light surrounding some object as if making a halo.
   • She was, as you know, to the west-ward of us, and the sunset was making a great flame of red light to the back of her, so that she showed a little blurred and indistinct by reason of the halation of the light, which...
2. The blurring of light around a bright area of a photographic image, or on a television screen.
   • As the result of a series of experiments on halation carried out with backed and unbacked plates, ordinary film and stripping film, Ernest Marriage concludes that there are two varieties of halation, one due to...
   • Halation, properly speaking, is the reflection and diffusion, within the film, from the lighter areas to the adjacent darker ones. - 1917, Photographers' Association of California, Camera craft, volume 24, page 81:
   • Among other interesting and weighty opinions, which were in general agreement with our contentions, was one by Mr. H. A. Staddon of Goodmayes, a gentleman who had made a particular hobby of fakes in photography. His...