aspect ratio« BACK TO DICTIONARY INDEX
(n.) Resolution expressed in relative height and width values. The standard ratio for computer screens historicaly was 4:3. This is the basis for the standard resolutions of 240:180, 320:240, 640:480, 800:600, 1024:768, and 1600:1200, all of which were used in digital video. The aspect ratio for television monitors is wider, and the problem of overscan introduces variables related to the safe viewing area around the edges. The ratio of modern motion pictures varies from 5:3 to 7:3, most often 16×9, creating a problem when a wide-format motion picture is transferred to a 4:3 ratio screen. A 35 mm photograph has dimensions of 36 mm x 24 mm, resulting in a 3:2 ratio. A letterbox effect occurs when photos are ported to the computer screen.