The majority of the Canon EOS SLR film cameras were manufactured to shoot 35mm film, a photographic roll film which is exactly 35mm wide. The film contains sprocket holes on both sides, so the serviceable35mm image area of the film becomes 24mm by 36mm size. The film comes in wound spools which are sealed inside a metal container (sometimes plastic) lightproof canister. Typically the film comes with either 24 or 36 frames (pictures) to a 35mm film roll.
35mm film, sometimes called 135 film after Kodak's original product number, is basically the only major camera film format most often used in today's world for still photography. 35mm is thought of as a small format as the negatives size is pretty small.
Mar 31, 2011