Instant film

Instant film is a type of photographic film introduced by Polaroid to be used in an instant camera (and, with accessory hardware, with many professional film cameras). The film contains the chemicals needed for developing and fixing the photo, and the instant camera exposes and initiates the developing process after a photograph has been taken.

In earlier Polaroid instant cameras the film is pulled through rollers which breaks open a pod containing a reagent that is spread between the exposed negative and receiving positive sheet. This film sandwich develops for a predetermined time, depending on film type and ambient temperature, after which the positive sheet is peeled away from the negative to reveal the developed photo.

In 1972, Polaroid introduced integral film, which incorporated timing and receiving layers to automatically develop and fix the photo without any intervention from the photographer.

Instant film is available in sizes from 24 mm × 36 mm (similar to 135 film) up to 50.8 cm × 61 cm size, with the most popular film sizes for consumer snapshots being approximately 83mm × 108mm (the image itself is smaller as it is surrounded by a border). Early instant film was distributed on rolls, but later and current films are supplied in packs of 8 or 10 sheets, and single sheet films for use in large format cameras with a compatible back.