HDTV Resolution Guide

The term ""1080p"" means 1080 horizontal lines, progressive. If that does not make much sense, it will at the end of this article.

Televisions create an image with thousands of square dots lined up, much like graph paper. 1080 means there are 1,080 rows of lines from the bottom to the top. The more lines there are, the smaller each individual dot becomes, making the final image sharper. To keep each dot square requires the grid to contain vertical lines as well. There are 1920 vertical lines and 1080 horizontal lines for a 1080p television, an aspect ratio of 16 X 9. For knowledge sake, dots on televisions are called pixels, and the number of lines, 1920 X 1080 is called the resolution.

This is a lot of information, but the take home message is this. More lines mean a clearer picture. It is important to remember that a television can display fewer lines, but not more lines. So, a 1080p television can display 720p without problems, but a 720p television cannot display 1080p.

Horizontal lines became the standard because a television draws images one horizontal line at a time. Progressive, the p in 1080p, means that all lines are drawn every cycle. This is opposed to interlaced, like standard definition or 1080i HD, which draws every other line each cycle, and can lead to a flickering image. The best DVD and Blu-Ray players output a progressive signal. For optimal results, a home theater system should feature a 1080p HDTV combined with a Blu-Ray player and an HD cable box that outputs a 1080p signal. More information on this, and other HDTV topics, can be found on our site.