What Is Film Halation?

Film halation is a phenomenon that occurs when light is reflected off the surface of a film negative, causing a halo or glowing effect around bright areas of the image. This can be caused by a variety of factors, including the type of film being used, the quality of the lens, and the lighting conditions.

Film halation is more likely to occur when shooting with film that has a low silver halide content, as these films are more susceptible to light leakage. It is also more likely to occur when shooting with lenses that have a lot of spherical aberration, as these lenses are more prone to scatter light. Finally, film halation is more likely to occur in low light situations, as the film emulsion is more sensitive to light in these conditions.

While film halation can be a desirable effect for some photographers, it can also be a problem if it is too pronounced or if it causes the image to look washed out or overexposed. To minimize film halation, photographers can use films with a higher silver halide content, use lenses with minimal spherical aberration, and avoid shooting in low light conditions.