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 closestobject; most of the time, that's true. But now and then, your camcorder may focus on something in the foreground that isn'tthe 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.
Fortunately, most DV camcorders offer a
manual focus