Many people think that when they buy a 16:9 television that they will no longer see black bars, not true. 16:9 or 1.78 aspect ratio is designed for High Def television. HD broadcasts will be done in a 1.78 aspect ratio.
DVD movies come in a variety of aspect ratio's, with the most common being 1.85 and 2.35. 1.85 is so close to 1.78 that it will be undetectable because of your tv/projectors overscan ability. When watching cinemascope movies of 2.35 or beyond (yes there is movies wider than 2.35) you will get black bars still. Also, when watching standard tv 4:3 or 1.33, you will have black bars on the sides on a widescreen tv.
