Overscanning and You

Every day, millions of TV viewers are blissfully unaware that they’re missing the big picture. In TV’s early days, the little cathode-ray guns inside the TV picture tube created an image by painting one line of the picture at a time, then turning around and heading back in the opposite direction, painting the second line. To make sure the screen was painted edge to edge, these early TVs overshot the edges of the screen—they overscanned the screen, to use the technical term.

Today, TV technology is much improved, but standard-definition tube TVs still overscan. The amount they do varies, but you may be missing as much as 10 percent of a picture beyond the left and right edges of the screen (and often beyond the top and bottom of the screen, too).