halationn.
/həˈleɪʃn/, U.S. /həˈleɪʃ(ə)n/, /heɪˈleɪʃ(ə)n/ 1. Photography. A halo-like effect in which light spreads beyond the edges of a bright object in a photograph, and which is principally caused by light striking the back surface of the base supporting the photographic emulsion and reflecting back into the emulsion at an angle, or by scattering of light within the emulsion itself.
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society > leisure > the arts > visual arts > photography > a photograph > qualities and effects > [noun] > indistinctness
veil1853
fogging1854
fog1856
halation1859
veiling1864
red fog1873
light fog1880
fuzz1889
soft focus1919
graininess1921
irradiation1924
unsharpness1961
1859 G. W. Perry Let. 12 Sept. in Photogr. Jrnl. 15 Nov. 91/2 The peculiar appearance (to which, until a better one is found, I have applied the term, ‘halation’) gives place to pure rich blacks, which contrast strongly with the brilliancy of the whites.
1881 Athenæum No. 2826. 857 Papers read: ‘Halation’, by Capt. Abney. This was shown not to arise from any turbidity in the glass, but from light being reflected from the back of the plate.
1916 J. Bernique Motion Picture Acting 182 White material, if starched or of silken sheen, will almost invariably produce halation. For this reason most studios avoid white in costumes.
1957 E. S. De Maré Photography vii. 152 In the case of an east window in a church, halation can only be avoided entirely by lighting the interior wall around the window, so reducing the contrast.
2010 J. A. Okun et al. VES Handbk. Visual Effects vii. 658 As a rule of thumb all effects that occur once light hits a camera lens should be done in the composite, which means that lens flares, blooms, halation, chromatic aberration of the lens, and the film's grain pattern should not be rendered.
2. An effect consisting of a series of halos of diminishing brightness surrounding the edges of a bright image on the screen of a cathode ray tube display, caused by internal reflection of the image-forming rays within the screen. Also: the reflection itself.
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society > communication > broadcasting > television > visual element > [noun] > television picture or image > defects in
multiple image1863
ghost1927
flicker1933
ion spot1936
halation1937
blooming1940
shading1940
misregistration1942
snow1946
snowstorm1948
ringing1949
streaking1956
strobing1961
flickering1968
1937 A. T. Witts Television Cycl. 56 Halation, the reflection of image rays by the back of a screen or film. Such reflection produces a blurring of the image as viewed by the observer, or is reproduced on the film.
1940 D. G. Fink Princ. Television Engin. iii. 72 The brightness contrast is limited by halation and saturation of the luminescent screen and by the defocusing effect (‘blooming’) associated with the electron gun when large signals are impressed upon it.
1958 Chambers's Techn. Dict. Suppl. 983/2 Halation, bright annular area around the cathode-ray tube phosphor spot, arising from internal reflection within the glass support.
2003 K. Compton Image Performance CRT Displays v. 47 Add in veiling glare, halation, and other inherent distortions that make the pixel larger, and the ideal pixel shape becomes awash in unwanted luminance energy.
This entry has been updated (OED Third Edition, June 2019; most recently modified version published online March 2022).
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n.1859