A Key Decision:
What is the best screen format?
Evan Powell, April 25, 2007
ProjectorCentral.com
These days conventional wisdom says that a new home theater should have a 16:9 projector and a 16:9 screen. For most people, that is absolutely right. Almost all of the latest plasma and LCD flatscreen TVs are in the 16:9 format, and most front projection home theaters are as well. But just because 16:9 has become the de facto standard, it doesn't mean it is right for you. You've got two good alternatives worth considering?going with a very large screen 4:3, or a super widescreen 2.35:1. Which of these formats is best for you? It all depends on the trade-offs you want to make, and how you want to manage your home theater experience. The purpose of this article is to describe your options and help you decide which way to go.
If you are new to the concept, when we talk about 16:9 or 4:3 or 2.35:1 formats, we're talking about the rectangular shape of the video image, or what is called its aspect ratio. The standard TV that's been around since the mid-50s has an aspect ratio of 4:3. That means the picture is 4 units wide for every three units of height. Meanwhile, the new HDTV standard is 16:9, which is 16 units of width for every 9 units of height. So HDTV's 16:9 is a rectangle that is, relatively speaking, horizontally wider than older TVs, which by comparison look almost square.
lots of info at:
http://www.projectorcentral.com/formats.htm