High Definition TV Resolutions: The Basics

What makes High Definition TV so great? Most HDTV watchers would tell you that it's simple: higher resolution. That's what sets HDTV apart from regular TV.

Regular television, or "standard definition" as it's also called, shows up to 480 pixels per line. It looks good if you've never experienced HDTV's higher resolution. With HDTV, the resolution depends on the source. There are two main source resolutions used in HDTV: 1080i and 720p.

1080i
1080i has a resolution of 1,920 by 1,080 pixels. This is a major improvement over standard definition television. CBS, NBC, Discovery Channel's HD broadcasts, PBS and the Xbox 360 all use this resolution. Of course, you can watch these stations on a lower resolution TV set, but if you have a 1080i set, you'll get the better resolution.

Also, 1080i is in a widescreen format. This is another great feature of HDTV.

720p
720p has a lower resolution. It's 1,280 by 720 pixels. Even though it has a lower resolution than 1080i, the difference is not as noticeable as the difference between either one and a standard definition TV. 720p also has the widescreen format. ABC, Fox and ESPN's HD broadcasts all use this resolution.

720p's resolution is lower, but it has a feature called "progressive scan" that 1080i doesn't. Progressive scan makes the movement on screen more fluid and realistic. Progressive scan makes the image move more smoothly.

480p
There is also a 480p format, which Fox uses for its digital broadcasts, but it's technically not HDTV, although it can be viewed on HDTV's. It's 852 by 480 pixels, widescreen and has progressive scan. Fox is the only network that uses this resolution, but some DVD players use it because of the smoother movement of progressive scan.

1080p
There is a newer format called 1080p which has the high resolution of the 1080i with the progressive scan of the 720p, but no network uses it yet. It's mostly a resolution format that some HDTV's are made in. According to reviews, 1080p isn't very much different than 1080i. Unless you have a large TV, like something over 46 inches, there's no noticeable difference.

The 1080p might be good for serious HDTV nuts. It does enable manufacturers to add special features, like increased contrast or better color. Unless you have a really good eye, you might not notice these differences, though. And, the 1080p sets usually cost quite a bit more than the others. In the next few years, there will probably be more reasonably priced 1080p sets. It's expected that more networks will begin taking advantage of 1080p's resolution and possibilities and begin broadcasting in 1080p. If this happens, 1080p sets may become a better buy.