Section 4.8. The Aspect-Ratio Problem

4.8. The Aspect-Ratio Problem

Lucky you: As a living witness to the Great Shift to High Definition, you're experiencing one of the most awkward times in all of video history.

Here's the problem. The shape of every TV set since its invention has been essentially the same: a slightly elongated square, with a width-to-height proportions of four-to-three. As engineers would say, you've been watching TV in a 4:3 aspect ratio your whole life.

But a high-def picture is different. It's widescreen, like a movie screenin a 16:9 aspect ratio. Most digital TV sets being sold these days have 16:9 widescreen proportions, and most camcorders sold today offer a 16:9 filming mode to match. (That includes standard-def camcorders, toonot just high-def ones.)

This all gets sticky, though, when you try to mix and match. For example, what if you own a widescreen TVand you try to play older, 4:3 videos on it? Or what if you have a traditional 4:3 TVand you try to play widescreen material on it?

You usually have two choices. Your TV can either fill in the rest of the screen with black bars, or stretch the picture to fit the screen it's on.

iMovie 6, too, now offers this option. Choose iMovie Preferences, click Import, and turn on "Automatic DV Pillarboxing & Letterboxing." Figure 4-10 shows the results.