Why are HDTV screens wider than regular TV screens?
For decades, our TV screens have been slightly wider than they are tall. Specifically, their ratio of width to height is 4 to 3, known as a 4:3 aspect ratio. Most HDTV screens, on the other hand, have an aspect ratio of 16:9, the same as many movie screens. That means television shows shot in wide-screen will look more cinematic, and many movies will fit on an HDTV screen without letterboxing (horizontal black bars at the top and bottom of the screen). There are exceptions, namely ultrawide “scope” movies such as Lord of the Rings and Star Wars, which still have letterbox bars on a wide-screen TV. Remember that not all HD programming is wide-screen, and when viewing either standard or high-def 4:3 programming on a wide-screen HDTV, you may get the opposite effect: vertical black or gray bars on the left and right of the screen.