AYRE DX-5DSD - Manual (Page 43)

The aspect ratios of video displays are usually given
as a ratio of integers. However as noted below, the
aspect ratios of films are usually normalized to one.
To make comparisons between video displays and
films easier, the ratios for displays can also be
normalized to one. Hence 16:9 becomes 1.78:1 and
4:3 becomes 1.33:1.
Aspect Ratios of Films
Nearly all films made from the 1920s through the
early 1950s used an aspect ratio of 1.37:1. To
compete against the threat of television, movie
studios began adding features such as color and a
wider (larger) picture.
Now nearly all films are made in a widescreen
format. The most commonly used aspect ratios
today are 1.85:1 and 2.35:1. This wider picture
allows for more dramatic and creative visual
compositions.
Matching Film to Display
When the aspect ratio of the film closely matches
the aspect ratio of the display, the film can easily be
viewed as the director intended. This happens when
watching a 1.37:1 film on a 1.33:1 standard video
display or when watching a 1.85:1 film on a 1.78:1
widescreen video display, as there is only a
negligible mismatch. But when there is a significant
mismatch, some action must be taken to allow the
film to be viewed without distortion.
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