Editing Negative pulldown (section)

== Usage of various formats ==
=== History ===
The majority of 35&nbsp;mm film systems, [[camera]]s, [[telecine]] equipment, [[optical printer]]s, or [[Movie projector|projector]]s, are configured to accommodate the 4-perf system; each frame of 35&nbsp;mm is 4 perforations long. 4-perf was (and remains) the traditional system, and the majority of projectors are based on 4-perf, because 4 perforations is the amount needed per frame vertically in order to have enough negative space for a roughly squarish image, which became the [[silent film]] standard [[Aspect ratio (image)|aspect ratio]] of 1.33:1. 

Later, when the film industry was facing the perceived threat of obsolescence to [[television]], universally a 1.33:1 aspect ratio at the time (and remained so in many countries until the introduction of [[Digital Television|DTV]]), studios started experimenting with various competing widescreen formats.