What is Halation?
In a photograph or an image, the spreading of light around the bright areas is called halation. Television and movie industries also employ the process of halation. Because of the halation, the final image has an ethereal and blurred quality about it. Some photographers may take halation as an annoying process while others may use it to obtain a certain look of a photograph or an image. Intentional or accidental halations can be created in a number of ways.
Normally in a photograph, the type of halation which is observed is undesired and accidental. The exposure of a light-sensitive emulsion which is present on a photographic film causes light to pass through it, but when the light bounces back, a blurred halo is created around areas of brightness. So, in order to prevent this effect, a coating of an anti-halation layer is provided by many photofilm manufacturers. To develop a normal film, the anti-halation layer is washed out while the film is being processed.
When disposable cameras or quickie labs are used by amateur photographers, halation may be seen after the film has been developed. These people normally blame the staff for it, but the real cause of the halation is in the film itself. However, if fogging or scratches are present on the image, the staff can be blamed as it shows that the film was handled carelessly when it was being processed.
Tricks of lighting are used when a photographer wants the halation effect deliberately. A particular type of developing paper and handling of the film is done inside the dark room to achieve this effect. A desired blurred and softened image can be achieved, as the halation effect can be controlled when it is desired by the photographer. Halation can also be used by experimental photographers. A striking memorable scene in the image can be created when halation is used deliberately.
The notification for the anti-halation layer can be seen on the general technical specifications of the film. However, a photographer who wants to experiment with the halation process can purchase a film which does not have an anti-halation layer. As both the styles are in demand, film manufacturers make films that have lines of film with or without the anti-halation layer. But it is recommended that a film with an anti-halation layer should be purchased by a photographer who doesn’t have much knowledge of halation, or often has to struggle with halation.
Category: Technology