Or without going elsewhere: Your TV is 16:9 - which is a 1.78 to 1 ratio. Many movies are transferred to DVD at a 1.78:1 ratio. But, MOST movies are actually wider than 1.78:1. Quite often, 2.35:1 and that is the way that they are put onto DVD. So, while you will find some DVDs that do completely fill your screen top to bottom. Most will still be somewhat letterboxed to preserver the original aspect ratio of the film as it was shot.