aspect ratio

Aspect ratio is the term for the relative length and width of an image on the screen based on how it was shot. The most common or standard aspect ratio in early films were called Academy Aperture (or ratio), at a ratio of 1.33:1 (the same as 4:3 ratio on a non-widescreen TV). Normal 35mm films are shot at a ratio of 1.85:1; new widescreen formats and aspect ratios were introduced in the 1950s, from 1.65:1 and higher. CinemaScope (a trade name for a widescreen movie format used in the US from 1953 to 1967) and other anamorphic systems (such as Panavision) have a 2.35:1 AR, while 70mm formats have an AR of 2.2:1; Cinerama had a 2.77:1 aspect ratio; letterboxed videos for widescreen TV's are frequently in 16:9 (or 1.77:1) AR.