Section 2.8. Keep It in Focus

2.8. Keep It in Focus

A camcorder is a camera, just like any other. If its lenses aren't focused on the subject, you wind up with a blurry picture.

In theory, the autofocus feature of every DV camcorder takes care of this delicate task for you. You point the camera, it analyzes the image and adjusts its own lens mechanisms, and the picture comes out in sharp focus. But in practice, the autofocus mechanism isn't foolproof. Camcorders assume that the subject of your filming is the closest object; most of the time, that's true. But now and then, your camcorder may focus on something in the foreground that isn't the intended subject. As a result, what you actually wanted to capture goes out of focus, as Figure 2-6 makes clear.

Another autofocus hazard is a solid or low-contrast background (such as a polar bear against a snowy background). The autofocus method relies on contrasting colors in the image. If you're aiming the camcorder at, say, a white wall, you may witness the alarming phenomenon known as autofocus hunting, in which the camcorder rapidly goes nearsighted, farsighted, and back again in a futile effort to find a focus level that works.

Other situations that freak out the autofocus include shooting when it's dark, shooting through glass, filming a subject that's not centered in the frame, and high-contrast backgrounds (such as prison or cage bars, French-window frames , and so on), which compete for the autofocus's attention.

2.8.1. Manual Focus

Fortunately, most DV camcorders offer a manual focus option: a switch that turns off the autofocus. Now you can (and must) set the focus by hand, turning a ring around the lens (or pushing + andbuttons) until the picture is sharp.

If neither you nor your subject has any intention of moving during the shot, that's all there is to manual focus. Moving shots are trickier, because as the distance between you and your subject changes, you may not have time to fiddle with the focus ring. The best approach is to keep the camera zoomed out all the way as you pan to track the action.

Another potential problem: zooming. When you zoom, your focus changes, too. Fortunately, there's an ancient and very clever trick that circumvents this problem: the zoom-out-and-focus trick. It goes like this:

1. Zoom all the way in to your subject.

   You haven't yet begun to record. You're just setting up the shot.

2. Focus the camcorder manually.

3. Zoom back out again.

   As you zoom out, notice what happens: The camcorder remains in perfect focus all the way. (Figure2-7 shows this sequence.) Now you can begin to film, confident that even when you zoom in, the picture will remain in sharp focus.

In other words, once you've focused at the maximum zoom level, you're free to set the zoom to any intermediate level without having to refocus ( if you're zooming sparingly and with a purpose, of course).