FILM

There are basically five categories of film - black & white, negative, slide, infra-red and instant. They can all be bought with varying speed ratings with an ISO (International Standards Organisation) number of 25 to 3200 although some films can exceed this. Whatever film you use, from instant to infra-red , any photograph produced can be scanned and stored digitally (see our Digital section).

Film Types:

The first film you will probably use would be negative (or print) film because this medium is the most convenient way to view or show your photographs. It is also the most forgiving of exposure errors as photo labs can adjust to lighten or darken the image if necessary. Negative film loses a degree of sharpness and definition due to the two processes required to produce the print ie: a print is taken from the negative. Slide (transparency) film, although less forgiving of exposure errors, produces superior results because there is no printing stage but it is possible to make prints from slides should you wish. They can be viewed by loupe,lightbox or projected onto a screen. This film is available in both daylight and tungsten balance (for use with artificial light). Instant film is only manufactured in print form and because it is processed 'instantly' it is ideal for those who cannot wait to view the results! Professionals will often use this method to preview a shot before committing it to film. All of the above- print, slide or instant - are available in colour or black and white. Infra-red is a specialist film, designed to produce specific effects by absorbing the infra-red spectrum of light.

Film Speed:

A film's speed is determined by the emulsion's sensitivity to light and therefore 'fast' film of ISO 400 or above need less exposure to light than a 'slower' film Faster film will produce a picture with more grain and may not be as sharp as that produced by the slower film and enlargements will reflect this. Film is a plastic base coated with silver salts (haladins) covered by a gelatine layer and it is the exposure time of light on the haladins that determines the 'graininess' of the photograph. It is usually the film's speed that will be the deciding factor when choosing the correct film for your subject matter. An ISO of 100 or 200 will be sufficient for shots taken outdoors on a bright day while indoors or in dim conditions you would require a ISO 400 or more. If it's movement you want to capture, then a faster film will 'freeze' the action whilst the slower speed will 'blur' it but film can be 'pushed' or 'pulled' to a higher or lower speed rating if you don't have the correct film to hand. Remember that slide film is more suitable to be altered than print but in any case you will have to let your processing lab know the film speed has been changed. When deciding on film a simple rule of thumb is that each doubling or halving of the speed is equal to one stop of light, for instance an ISO 400 is twice as fast as an ISO 200.

Personal Preferences:

You will find that different makes of film give different results - this is because there are colour differences between manufacturers products. Only by trial and error will you discover the film best suited to your requirements. Most modern film emulsions produce excellent results but due to the colour differences some types are more suited to certain subjects than others, although there may be times when a slight colour cast can be beneficial. An important point to remember with all film is that correct storage is desirable - film will deteriorate quickly if subjected to heat, humidity or harsh light. The ideal storage facility is in a sealed container in the refrigerator but allow the film to stand at room temperature before use to avoid condensation.