16 mm is a narrow film format that is used mainly for small format display and photography. 16 mm has an aspect ratio of 10.3 x 7.5 mm (width x height) and can be perforated on one side (single sprocket) as well as on both sides (double perforation); the diagonal size is 1/2 inch or 12.7 mm. Single sprocket 16 mm film can be exhibited with an optical or magnetic sound track. 16 mm film was introduced in 1923 and has since served as a less expensive alternative to the 35 mm Cinema standard. The 70 percent size reduction in 16 mm from 35 mm means the picture quality is considerably reduced. For this reason, 16 mm film is mostly used for television productions and low budget films.