Fullscreen (aspect ratio)
Full screen or fullscreen refers to the 4:3 (1.33:1) aspect ratio of early standard television screens and computer monitors. The 4:3 aspect ratio became the standard in film because it mirrored film stock and was the easiest to use. Widescreen ratios started to become more popular in the 1990s and 2000s.
Film originally created in the 4:3 aspect ratio does not need to be altered for full screen release, while other aspect ratios can be converted to full screen using techniques such as pan and scan, open matte or reframing. 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.