Anti-halation backing

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (July 2009)

An anti-halation backing is a layer found in most photographic films. It is usually a coating on the back of the film base, but sometimes it is incorporated between the light-sensitive emulsion and the base. The light that passes through the emulsion is absorbed by the anti-halation layer. This prevents any light from being reflected back through the emulsion from the rear surface of the base, or from anything behind the film, and causing a halo-like effect around bright points or edges in the image. The anti-halation layer is rendered transparent or washed out (as in K-14 films) during processing of the film.

The lack of an anti-halation layer in Kodak's High Speed Infrared film (HIE) is the cause of the ethereal "glowing" effect often associated with infrared photography^[1], rather than an artifact of IR itself.

References

This photography-related article is a stub. You can help Wikipedia by expanding it. v d e