120 Roll Film and Related Frame Sizes

Film Photography

120 roll film format was introduced by Kodak for their Brownie No2 in 1901

Fujifilm Pro 400It was originally intended for amateur photography but was later superseded in this role by 135 film. 120 film and its close relative, 220 film, survive to this day as the only medium format films that are readily available to both professionals and amateur enthusiasts.

The 120 format is typical of roll film. The spool originally was made of wood with metal flanges, later all metal, and now made of plastic. Frame number markings for the three standard image formats are printed on the backing paper. The film is 72 cm (28.3 inches) long.

The specifications for 120 and 220 film are defined in the ISO 732 standard. Earlier editions of ISO 732 also provided international standards for the now-obsolete 127 and 620 film formats.

Frame sizes

120 film allows several frame sizes.

120 frame sizes

Name Aspect ratio Nominal size (mm) Exposures
6 × 4.5 1.35:1 56 × 41.5 15 or 16
6 × 6 1:1 56 × 56 12
6 × 7 1.25:1 56 × 70 10
6 × 8 1.37:1 56 × 77 9
6 × 9 1.50:1 56 × 84 8
6 × 12 2.1:1 56 × 118 6
6 × 17 3:1 56 × 168 4
6 × 24 4:1 56 × 224 3

†Due to better control of frame spacing, newer 6×4.5 format cameras can fit 16 exposures onto a roll of 120

The 6×9 frame has the same aspect ratio as the standard 36×24 mm frame of 135 film. The 6×7 frame enlarges almost exactly to 8×10 inch paper, for which reason its proponents call it "ideal format". 6×4.5 is the smallest and least expensive roll-film frame size; equipment to take photos in this size is also the lightest.

The wide 6×12, 6×17, and 6×24 cm frames are produced by special-purpose panoramic cameras. Because of the need to cover such a wide piece of film, most of these cameras use lenses intended for large format cameras.

Cameras using 120 film will often combine the numbers of the frame size in the name e.g. Pentax 67 (6×7), Fuji 617 (6×17), and many 645s (6×4.5).

Roll film

Original 120, 620 and modern 120 film spools with modern 120 exposed color film
Original 120, 620 and modern 120 film spools with modern 120 exposed color film
Rollfilm or roll film is any type of spool-wound hotographic 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. 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.

Rollfilm was invented in 1981 by David Houston (a photographic inventor from Hunter, ND, who held the patents to several roll film camera concepts that he later sold to George Eastman) and first used in his Kodak box camera of 1888. Roll film remained the format of choice for inexpensive inexpensive snapshot cameras through the end of the 1950s, the most common sizes being 127 and 828 for small format cameras and 120 and 116 for medium format cameras. Roll film was also used by high-class professional cameras like the Swedish-made Hasselblad. The use of roll film in snapshot cameras was largely superseded by 135 and 126 cartridges, but 120 and 220 film is still commonly used in medium format cameras.

Other similar 6 cm roll films

105 format was announced by Kodak in 1898 for their first folding camera and was the original 6×9 cm format roll film. The 117 format was introduced by Kodak in 1900 for their first Brownie camera, the No.1 Brownie, 6×6 cm format. These formats used the same width film as 120 film, but with slightly different spools. The 105 spool has a much wider flange, similar to the 116 spool. The 117 spool is slightly narrower than the 120.

620 format was introduced by Kodak in 1931 as an intended alternative to 120. Although mostly used by Kodak cameras, it became very popular. The 620 format is essentially the same film on a thinner and narrower all-metal spool (the 120 spool core was made of wood at that time):

120 2.466" width, 0.990" flange, 0.468" core 620 2.468" width, 0.905" flange, 0.280" core Hence the 620 is sometime referred as "small hole" 6×6 or 6×9 as opposed to 120 "large hole". The 620 format was discontinued by Kodak in 1995, but it is possible to rewind 120 film onto a 620 spool in the darkroom for use in 620 cameras. According to Kodak, the narrower metal spool allowed building smaller cameras. Nonetheless the 120 format cast-metal bodied Voigtländer Perkeo remains smaller than any 620 format camera.

original 120 spool
Original 120 spool (left) versus a 620 spool
The 220 format was added in 1965 and is the same width as 120 film, but with double length (144 cm) film and has twice the number of exposures per roll. In 6×6cm cameras, there are 24 exposures. Unlike 120 film, there is no backing paper behind the film, just a leader and a trailer. This results in a longer film on the same spool, but there are no printed frame numbers. Also, it cannot be used in unmodified old cameras that have a red window as frame indicator. Moreover, since the film alone is thinner than a film with a backing paper, a special pressure plate may be required to achieve optimal focus if the film is registered against its back side. Some cameras capable of using both 120 and 220 film will have a two position adjustment of the pressure plate (e.g. the Mamiya C220 or Mamiya C330) while others will require different film backs e.g the Pentax 645 or Kowa Six).

ISO 732

ISO 732 is an ISO standard for medium format photographic film. The second (1982) edition of the standard specified the dimensions for 127, 120 and 620 roll film, backing paper and film spools. The third (1991) edition dropped specifications for the 127 and 620 roll films, which had become largely obsolete in the photography industry and added specifications for 220 roll film. The current (2000) edition incorporates the now withdrawn standard ISO 1048 on identification of exposed roll films.

120, 220, and 620 film are closely related formats, using film rolls of the same width, while 127 film is smaller in width. The formats and their names predate ISO standardization and were developed by Kodak.

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Updated Oct 15, 2014

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