HDTV Basics

Screen Resolution
The resolution of a TV screen refers to the number of pixels in the image, just like in a computer screen or a digital camera. But instead of "megapixels", TV resolution is measured by the number of pixel rows. Combine the number of rows with the display type (p or i), and you get the resolution class. Some resolution classes that you may have heard of include 480p, 720p, 1080i, and 1080p.

As of early 2007, the most popular HDTV resolutions are 720p and 1080i. Even though a 720p set has lower resolution than a 1080i, it does not look worse in general, since the progressive scan displays smoother motion. The only reason 1080p is not more popular is because it's more expensive and there aren't many sources of 1080p content yet. But, that is changing, and 1080p will probably be the standard for HDTV in a few years.

Display Format
Every TV has a distinct size and Aspect Ratio. The size is simply the diagonal measurement of the screen, as shown in the picture.

The Aspect Ratio describes the shape of the screen. A TV with a 4:3 aspect ratio is 3/4 as high as it is wide, and a TV with 16:9 aspect ratio is 9/16 as high as it is wide. That's all there is to it.

The 4:3 ratio comes from a somewhat arbitrary decision, made many decades ago, that determined the shape of a frame on a reel of 35mm movie film. When television was born, this aspect ratio was used by default. Now that flat panel HDTVs are on the scene, and are easy to make in any size or shape, the superior 16:9 format is becoming the new standard.

Adjusting to HDTV
Watching things on your HDTV is a little more complicated than on a regular TV, but not much. When switching from regular to HDTV you'll need to get a few things in addition to the TV itself: