A full-screen video is a film that has been altered to the 4:3 (or 1.33:1) aspect ratio of the old standard television screen. Full Screen is usually created by either pan and scan, open matte or reframing. Films created in the 4:3 aspect ratio do not need to be altered.
In pan and scan, the 4:3 image is extracted from within the original frame by cropping the sides of the film. In open matte, the 4:3 image is extracted from parts of the original negative which were shot but not intended to be used for the theatrical release. In reframing, elements within the image are repositioned. Reframing is almost exclusively a method used for entirely CG movies where the elements can be easily moved.
Full-Screen aspect ratios in standard television have been in use since the invention of moving picture cameras. Older computer monitors employed the same aspect ratio. 4:3 was the aspect ratio used for 35 mm films in the silent era. It is also very close to the 1.375:1 Academy 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, movies originally photographed on 35 mm 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) to differentiate the film industry from TV. However, since the start of the 21st-century broadcasters worldwide are phasing out the 4:3 standard entirely, as manufacturers started to favor the 16:9/16:10 aspect ratio of all modern high-definition television sets, broadcast cameras, and computer monitors.