Aspect ratio

A short history of aspect ratio

Aspect ratio is the relationship between the width and height of the picture as it is displayed on a screen. In the silent era of cinema, aspect ratio was fixed at 4×3 (1.33:1). When sound was first introduced, the ratio was reduced to accommodate a soundtrack. This ratio is known as Academy.

Academy ratio (1.37:1) was used for the majority of films made between the 1930s and 1950s (and is roughly 4×3). It is also a common aspect ratio for standard 16 mm. When television was introduced, it also retained this 4×3 ratio. A number of television films and programs continue to use this aspect ratio.

With the introduction of television in the 1950s, cinema had another medium to compete with and the industry began using wider screening ratios. Cinemascope (2.35:1/2.39:1) uses an anamorphic camera lens to distort or ‘stretch’ the image into the available space on a 35-mm frame. When projected, a similar lens is used to display an undistorted image, where the horizontal dimensions are twice that of the vertical dimensions.

The US and UK widescreen standard for 35-mm film is 1.85:1. 16×9 or 1.78:1 is the standard aspect ratio for widescreen and high definition television. Widescreen films sacrifice the top and bottom of the film frame, in order to achieve a longer, rectangular image on screen.

Original aspect ratio (OAR) refers to the aspect ratio in which the filmmaker intended the film to be viewed.

Clips displayed on the australianscreen website

australianscreen endeavours to present and display audiovisual material in an aspect ratio that is as close to the original intended ratio as possible. Filmmakers have been contacted to ascertain the original aspect ratio of their works but where the filmmaker has been uncontactable or the original aspect ratio is unclear, expert staff at the National Film and Sound Archive have assessed the films based on their specialist knowledge to determine the correct aspect ratio.

The display settings for the media players used on this site are able to play clips in the five most common aspect ratios. We have standardised some aspect ratios to limit the number of web page templates as illustrated in the following table: