The 4:3 ratio for standard television has been in use since television's origins and many computer monitors use the same aspect ratio. 4:3 is the aspect ratio defined by the Academy of Motion Picture Arts and Sciences as a standard after the advent of optical sound-on-film.

Matching this aspect ratio meant that films previously photographed on film could be satisfactorily viewed on TV in the early days of the medium. When cinema attendance dropped, Hollywood created widescreen aspect ratios to immerse the viewer in a more realistic experience and, possibly, to make the cinema experience more of a spectacle that could not be achieved at home on a regular TV set.

16:9 is the international standard format of HDTV as used in Australia, Japan an United States, as well as in Europe on satellite and non-HD widescreen Television (EDTV) PAL-plus. Japan's Hi-Vision originally started with a 5:3 ratio but converted when the international standards group introduced a wider ratio of 5⅓ to 3 (=16:9). Many digital video cameras have the capability to record in 16:9.

Anamorphic DVD transfers store the information in 16:9 vertically stretched to 4:3; if the TV can handle an anamorphic image the signal will be de-anamorphosed by the TV to 16:9. If not, the DVD player will un-stretch the image and add letterboxing before sending the image to the TV. Wider ratios such as 1.85:1 and 2.40:1 are accommodated within the 16:9 DVD frame by adding some additional black bars within the image itself.

Two aspect ratios compared with images using the same vertical size.

4:3
16:9