Film cassette

135 is photographic film in a film format used for still photography. It is a cartridge film with a film gauge of 35 mm, typically used for hand-held photography in 35 mm film cameras. Its engineering standard for the film is controlled by ISO 1007.

The term 135 (ISO 1007) was introduced by Kodak in 1934 as a designation for the cassette for 35 mm film, specifically for still photography. It quickly grew in popularity, surpassing 120 film by the late 1960s to become the most popular photographic film size. Despite competition from formats such as 828, 126, 110, and APS, it remains so today.

135 camera film always comes perforated with Kodak Standard perforations.

The size of the 135 film frame has been adopted by many high-end digital single-lens reflex and digital mirrorless cameras, commonly referred to as "full frame". Even though the format is much smaller than historical medium format and large format film, it is much larger than image sensors in most compact cameras and smart phone cameras.

Individual rolls of 135 film are enclosed in single-spool, light-tight, metal cassettes to allow cameras to be loaded in daylight. The film is clipped or taped to a spool and exits via a slot lined with flocking. The end of the film is cut on one side to form a leader. It has the same dimensions and perforation pitch as 35 mm movie print film (also called "long pitch", KS-1870, whereas 35mm professional motion picture camera films are always "short pitch", BH-1866).

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