CNET's quick guide to aspect ratio
By John P. FalconeFeb 19, 2008
It's a familiar story: You've just invested thousands of dollars in a new TV, but all the actors on your favorite shows look unnaturally bloated and fat. Or there are black bars at the top and bottom of the screen--and on the left and right. Or everything on your favorite DVDs looks tall and skinny. All of these problems are examples of one of the most important--and least understood--issues in the home-theater world: aspect ratio. We'll take you step by step through the common aspect-ratio problems--and their solutions--on both standard and wide-screen televisions.
1. What is aspect ratio?
The concept is simple enough: aspect ratio is the fractional relation of the width of a video image compared to its height. The two most common aspect ratios in home video are 4:3 (also known as 4x3, 1.33:1, or standard) and 16:9 (16x9, 1.78:1, or wide-screen). All the older TVs and computer monitors you grew up with had the squarish 4:3 shape--only 33 percent wider than it was high. On the other hand, 16:9 is the native aspect ratio of most HDTV programming; it is 78 percent wider than it is tall, or fully one-third wider than 4:3.
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At comparable screen sizes, the wide-screen image is a distinct improvement: it offers a larger image, and the horizontal orientation is more akin to how your eyes--next to each other, not on top of one another--view objects.
Both of these formats work perfectly well when they match the TV screen's native aspect ratio--standard programming on a 4:3 screen (any 1950s to 1990s Nick at Nite fare, for instance) and any newer, wide-screen material on a 16:9 set (HDTV programming or most DVDs). But as soon as you try to watch 4:3 content on a wide-screen monitor or 16:9 content on a 4:3 TV, you need to make some choices as to how you'll compromise.
