One of the most common questions from new widescreen TV owners is: “Why are there black bars on my widescreen TV?” The simple answer is that your TV and the video you watching have different aspect ratios. There is nothing wrong with your TV.
This “pillar box effect” most often happens when you are watching a video or broadcast that was shot in standard definition with an aspect ration of 4:3. Because your widescreen TV has an aspect ration of 16:9, the picture can not properly fill the entire screen.
Almost all modern widescreen TVs have a “wide” or “zoom” function that will allow you to completely fill the screen. Unfortunately when you choose one of those modes the picture will either appear stretched out of proportion (because it is) or part of the picture will be cut off. You will want to play with these modes to see if one of them is suitable to your needs. You may prefer to continue watching in the original 4:3 mode with the black bars around the image. But be careful, on some plasma TVs this may cause plasma screen burn in.
It’s important to note that many movies you get on HD-DVD or Blu-ray discs will have an aspect ration of 1.85:1, which instead of causing black bars to appear on the side of your screen will cause them to appear at the top and bottom. You can deal with this effect in the same way as with the pillar effect. Simply use zoom or fill to get the picture to fill up your screen completely. In this case you may not fine the black bars as undesirable because the picture will already be filling up most of your screen.