letterbox(redirected from Gutterbox)
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letterboxThe visual effect when a wide screen movie is displayed on an earlier standard TV (SDTV) set. The video frame spans the full width of the TV screen, but because of the difference in aspect ratios (wide screen movie vs. more square TV screen), the vertical height of the frame is reduced. The unused top and bottom areas of the screen appear as black bars.
Black Bars Are Still Present
Many major motion pictures are shot in full panoramic format with aspect ratios that are even wider than today's 16:9 wide screen TVs. As a result, the letterbox black bars still show, although not as thick as when displayed on a standard 4:3 screen (see aspect ratio for comparison). The term "letterbox" was coined because the wide frame resembles a letter envelope. Contrast with pan & scan. See pillarbox and anamorphic DVD.
|Standard Vs. Wide Screen TV|
|When a wide video or movie plays on a standard TV (left), the image is reduced vertically, producing the letterbox effect. (Image courtesy of Intergraph Computer Systems.)|