4:3 is the aspect ratio used for 35 mm films in the silent era and used today for film production under the name Super 35. It is also very close to the 1.37:1 aspect ratio defined by the Academy of Motion Picture Arts and Sciences as a standard after the advent of optical sound-on-film. By having TV match this aspect ratio, films previously photographed on film could be satisfactorily viewed on TV in the early days of the medium (i.e. the 1940s and the 1950s). When cinema attendance dropped, Hollywood created widescreen aspect ratios (such as the 1.85:1 ratio mentioned earlier) in order to differentiate the film industry from TV.

See also:

• tag group:aspect ratios – for common aspect ratios