Sizes and Packings
The broadest array of color and black-and-white emulsions is predominantly available in the 35 mm (135) size. Initially designed for cinematic use, 35 mm film was later embraced by photographers for its convenience and quality. This film is typically provided in cassettes that yield up to 36 exposures of the standard 24×36mm format. Additionally, a limited selection of 35 mm films can be obtained in bulk lengths of 15m and 30m (or 50ft and 100ft) stored in tins.
This bulk film is intended for use with cameras equipped with specialized film backs or can be cut into shorter lengths to refill standard reloadable cassettes. Although reloading film can reduce costs, it carries the risk of scratches and dust contamination, making it generally impractical for professional use. Medium format film, commonly referred to as ‘120’, is rolled with opaque backing paper on a spool and is 62 mm in width. The number of images per film roll varies depending on the camera’s picture format. ‘220’ film, characterized by a thinner base, offers twice the length and number of exposures as ‘120’ film but is declining in popularity due to its increased susceptibility to damage.
Sheet films, available in packs of 10, 25, or 50, come in several standard sizes such as 4×5 inch and 8×10 inch. These films feature edge-notching to assist in locating the emulsion surface when loading film holders in the dark, with a shape code for tactile identification of film type and post-processing recognition. Roll films possess further type and batch identification data printed along their edges, which can be decoded using the manufacturer’s datasheet.
Instant print sheet materials are primarily used in packs of 8 or 10 exposures of sizes 3¼×4¼ inch and 4×5 inch, or individual sheets of 4×5 inch and 8×10 inch within special envelopes. They come in two main varieties: ‘peel apart’ and ‘integral’. Each exposure on peel-apart material is removed from the camera as a sandwich of two sheets, which are left together for a specified period before being peeled apart to reveal a positive print on one sheet. This type is often used in a pack holder that attaches to 120 cameras with magazine backs or 35 mm cameras with removable backs. Sheet instant film fits into a specialized holder for view cameras, which also contain the roller mechanism necessary for spreading the chemical gel during processing. Peel-apart materials remain popular among professional photographers in studio settings to produce quick proof prints for verifying lighting, exposure, and composition. However, the colors may not precisely match those of conventional color film.
‘Integral’ instant picture prints are ejected from the camera as plain cards that develop into images before the viewer’s eyes. Primarily used in Polaroid point-and-shoot cameras equipped with internal mirrors to correct the left-to-right reversal, these materials are becoming scarce since Polaroid ceased production in 2008, although Fuji continues to offer instant films.
APS (Advanced Photo System) camera films are 24 mm wide and housed in cartridges that automatically open and load when inserted into the camera body. The picture format is 17×30mm, cropped by the camera during shooting. Cartridges offer 15, 25, or 40 exposures and are returned from the lab with the processed negatives sealed within, not designed to be opened. Mechanized printing machinery retrieves the film for reprints, although hand printing necessitates breaking open the cartridge. APS never gained significant traction among professional photographers due to its smaller film size, constituting just 56% of a 35 mm frame, and the format was soon overshadowed by digital cameras. Kodak, the format’s introducer in 1996, ceased producing APS cameras in 2004, though a limited range of APS films remains available.
Other film formats are seldom encountered but are manufactured for specialized applications in science and industry. For instance, astronomers sometimes require exceptionally flat negatives, which are more dimensionally stable than acetate film, thus still using traditional glass plates despite the prevalence of CCD arrays.
