The aspect ratio is mathematically expressed as x :y and it represents an picture with its width divided by its height. Most common aspect ratios are 4:3 (1.33:1) universal for standard-definition video formats and 16:9 (1.78:1), universal to high-definition television. Other popular aspect ratios are 3:2 (1.50:1), found in 35mm film still used in photography, 1.85:1 and 2.39:1 used for presentation of films in movie theaters.
Other aspect ratious:
- 1.37:1 - Nearly universal in cinema films made between 1932 and 1953.
- 1.43:1 - Also known as Imax format.
- 1.56:1 - Widescreen aspect ratio 14:9, this was compromis format between 4:3 and 16:9 formats.
- 1.66:1 - Flat ratio invented by Paramount Pictures
- 1.75:1 - Used by MGM and Warner Bros. between 1953 and 1955.
- 2.00:1 - Flat ratio used in some American studios in the 1950s.
- 2.20:1 - 70 mm standard, developed for Todd-AO in the 1950s.
- 2.35:1 - Often commercially branded as Panavision format used in 1970s.
- 2.55:1 - Original aspect ratio of CinemaScope before optical sound was added to the film.
- 2.59:1 - Cinerama, three specially captured 35 mm images projected side by side into one widescreen image.
- 2.66:1 - Full frame output from Super 16 mm negative.
- 2.76:1 - MGM Camera 65 used only on a handful of films between 1956 and 1964.
- 4.00:1 - Polyvision, three 35 mm (1.33:1 x 3) images projected side by side.
