A:Answer Hi Bill, my simplest answer is... HD picture is in a rectangular shape, like your tv. SD picture is in a square shape, like tvs of years ago. You can have the SD pictues stretch across the entire tv (by changing settings), however this will result in a distorted image. The tv knows what pictures are in SD, and creates the bars or margins on itself so the picturs will look normal. You may want to see if this tv has a zoom setting for SD chanels in settings. This might fill the screen, but may cut off the edges due to "blowing up" the picture. Hope this helps you to understand better how the display works.
