Wide-screen movies may not automatically adjust on big new set

June 15, 2006

By Jim Rossman / The Dallas Morning News

Jim Rossman is your Tech Adviser offering advice and tips for computer hardware and programs. Helpful links are included. Jim Rossman is technical manager of Macintosh support for Belo Corp.

Q: We just bought our first big-screen TV — a 42-inch plasma — and we are confused about something.

I thought all my wide-screen DVD movies would fill the screen instead of giving me those black bars above and below the picture. But there are still black bars.

Why can't things be easy?

— J.L., Dallas

A: Welcome to the confusing world of aspect ratios. Let's start at the beginning.

Most televisions made with a CRT (tube) have an aspect ratio of 4:3. This means the picture is 4 inches wide for every 3 inches it is tall.

More recently, TV manufacturers have begun to sell wide-screen CRTs.

Almost every big-screen TV, including plasma and LCD flat screens, has an aspect ratio of 16:9, which factors down to about 1.78:1. It is almost twice as wide as it is tall.

High-definition TV uses a 16:9 aspect ratio.

Trouble enters the picture because most wide-screen movies are shot at aspect ratios that are not 16:9.

I rented two DVDs this weekend — one was 1.85:1 and the other was 2.25:1.

Your TV will show black bars above and below the image. This is called letter-boxing.

Also, as long as we're talking about terms, the display of standard definition (4:3) programming on a wide-screen TV is called pillar-boxing.

You are probably not stuck with the letter-boxing if you are willing to take a slight change in the image on the screen.

Wide-screen TVs can enhance the picture by zooming or stretching the picture to fill the screen.

Today's TVs will usually let you choose from several picture modes to fill the screen.

Unfortunately, every television manufacturer has a different set of picture modes and a different term for them in the instruction book, as well as different buttons on their remotes.

Everyone who gets a wide-screen TV plays with these settings when they discover much of the content on TV does not fill the screen naturally.

Play around with the settings on your set.

You'll find one that works pretty well for you.

If you'd like to read about aspect ratios, try en.wikipedia.org/wiki/Aspect_ratio_(image).