It's because the source (disc player, cable box, satellite receiver) is sending a 16:9 widescreen signal to the TV. This will automatically put itself in the 16:9 widescreen mode (High Definition) (See Fig. B below).
If the source sends an SD 4:3 signal to your TV, the TV will automatically put itself in the 4:3 mode (Standard Definition). (See Fig. A).
Sources suggest that if the player is set to output a 16:9 signal to your TV, the player then stretches the letterbox movie vertically so the black bars at the top and bottom are gone. This makes the people and objects look tall and thin.
When considering buying a brilliant TV to stand against or hang from a wall as the centerpiece of a living room, many people think about just two factors: How big it is, and how much it is.
For some people, buying a TV may never come down to anything more than that. But if you truly want to get the most for your money, you’ll want to understand what’s really going on with the TVs you check out. Here are 9 must-know tips before you buy a new TV shared by Cheatsheet.com.