iMovie '09 & iDVD: The Missing Manual

Phase 1: Prepare Your Video

For the most professional results, prepare your video in iMovie (or another video editing program) before importing it into iDVD. Here are a couple of key issues to keep in mind.

Overscanning and You

Millions of TV viewers every day are blissfully unaware that they're missing the big picture. In TV's early days, the little cathode-ray guns inside the TV worked by painting one line of the TV picture, then turning around and heading back the opposite direction. To make sure that the screen was painted edge to edge, these early TVs were programmed to overshoot the edges of the screen—to use the technical term, to overscan the screen.

TV technology is much better now, but even modern standard-definition tube TVs exhibit overscanning. The amount varies, but you may be missing as much as 10 percent of the picture beyond the left and right edges (and often the top and bottom, too).

TV producers are careful to keep the action and titles in the part of the frame that's least likely to be lost in the overscan. If you plan to edit your film, the TV-safe area is suddenly your concern, too. The overscanning effect means that when you show your iMovie productions on a TV, you'll lose anything that's very close to the edges of the frame. In particular, broadcasters refer to two danger margins of a video image: the title-safe area and the action-safe area (see Figure 16-1).

Note

Flat-panel TV sets like plasmas and LCDs don't have picture tubes, and therefore don't overscan. ...