Widescreen Displays
Let’s start with a widescreen movie shot in 1.85:1 and viewed on a 1.78:1 widescreen video display. In this case virtually the entire image can be seen with no adjustments required. The film is presented in the same way as in a movie theater.
If we want to now watch a standard movie shot in 1.37:1, we run into a problem. The narrower picture automatically fills up the screen, stretching and distorting the image.
This is clearly unacceptable, so we use the “Aspect Ratio” control on the video display to shrink the image horizontally, restoring the proper geometry. The display device also adds black (or sometimes grey) vertical bars on each side of the picture. These correspond to the movable curtains used to block part of the screen in a movie theater.
A few widescreen displays erroneously lack an “Aspect Ratio” control when fed a progressive video signal. In this case, standard films are unavoidably stretched to fill the display. One workaround for this problem is to feed both progressive and interlaced signals to the display. When watching a standard (1.37:1) film, select the interlaced input on the video display to allow adjustment of the aspect ratio.
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