Issues with Film Aspect Ratios
While 16:9 is a fairly wide aspect ratio, it is not wide enough to contain an entire frame
from a typical Hollywood movie. Two film aspect ratios are widely used now: Normal is
1.85:1 and Widescreen is 2.40:1 (for comparison, 16:9 is 1.78:1). For normal titles (those
that use the 1.85:1 aspect ratio), a small amount of letterboxing or pan-scan cropping is
required to transfer the title to DVD, but for Panavision titles significant letterboxing or
pan-scan cropping is necessary. This processing must be done before the video is
MPEG-encoded. The DVD specification supports only 4:3 and 16:9 aspect ratios.
1.85:1 (Normal film)
You should not be surprised to see some letterboxing when playing a Panavision movie
on a 16:9 monitor.