When you watch a wide-screen movie on a TV set (or on your computer), you often get black bars across the top and bottom to “letterbox” the film, which makes it seem small. It makes you want to go buy a bigger TV! Why did movie formats become so incompatible with TV formats? It started in earnest in 1953 when movie producers wanted to make the theater experience better than watching TV at home. We got Cinemascope, Cinema, and Panavision, all glorious wide-screen formats that became all the rage before Hollywood confronted what happens when those movies were later shown on television.
Many television networks decided to tackle the issue by using "pan-and-scan" versions of the films, which basically involved a film engineer selectively focusing on small parts of the screen and shifting the layout so as to match what was happening on the screen.
This technique, as you imagine, has some really negative effects on the films that used it. If a film was framed so that two people were standing far apart, for example, one would inevitably be cut off. Panning-and-scanning could hide moments of tension or even remove key characters from a scene.
There are videos that compare the pan-and-scan with the original versions that make this clear. After you get a glimpse at what you miss in the movies, you don’t mind the more modern letterboxing so much. Read about the history of letterboxing at Atlas Obscura.
(Image credit: Bubba73 (Jud McCranie))