Roll film

Rollfilm or roll film is any type of spool-wound photographic film protected from white light exposure by a paper backing, as opposed to film which is protected from exposure and wound forward in a cartridge. The term originated in contrast to sheet film. Confusingly, roll film was originally often referred to as "cartridge" film because of its resemblance to a shotgun cartridge. The opaque backing paper allows roll film to be loaded in daylight. It is typically printed with frame number markings which can be viewed through a small red window at the rear of the camera. A spool of roll film is usually loaded on one side of the camera and pulled across to an identical take up spool on the other side of the shutter as exposures are made. When the roll is fully exposed, the take up spool is removed for processing and the empty spool on which the film was originally wound is moved to the other side, becoming the take up spool for the next roll of film.

In 1881 a farmer in Cambria, Wisconsin, Peter Houston, invented the first roll film camera. His younger brother David, filed the patents for various components of Peter's camera. David Henderson Houston (b. June 14, 1841; d. May 6, 1906 ), originally from Cambria, Wisconsin, patented the first holders for flexible roll film. Houston moved to Hunter in Dakota Territory in 1880. He was issued an 1881 patent for a roll film holder which he licensed to George Eastman (it was used in Eastman's Kodak 1888 box camera). Houston sold the patent (and an 1886 revision) outright to Eastman for $5000 in 1889. Houston continued developing the camera, creating 21 patents for cameras or camera parts between 1881 and 1902. In 1912 his estate transferred the remainder of his patents to Eastman.

The most popular rollfilm is the type 120 film format, which is used in most medium-format cameras and roll film magazines for large-format cameras. Until the 1950s, 120 roll film was also used in the then most simplist of snapshot cameras, and box cameras. The use of roll film in consumer cameras was largely superseded by 135 and 126 cartridges, but 120 and 220 (double length) film are still commonly used in medium-format cameras.

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