Digital cameras normally tout both optical and digital zooms. Then they multiply them. They want to leave you with the impression that you can photograph a bee in the next county. But it is all pretty misleading, because digital zoom isn't terribly useful.

Here's why: Let's say you're taking a picture of a distant peak. That peak takes up 40 percent of the picture, as shown on your LCD screen. You can use digital zoom to crop extraneous material. Now, the peak is enlarged, taking 100 percent of the LCD screen.

In performing this transformation, the camera simply spreads the remaining pixels when the picture is cropped. So you'll probably get a grainy picture.

I don't have a lot of use for digital zoom. So, I don't pay attention to those numbers when I look at a camera. And I ignore the multiplication (digital zoom times optical zoom) done by the marketers.

The other zoom is optical. And, unlike digital, optical zoom is very important. To see why, let's look at that mountain peak again.

Cameras with optical zooms typically have a lever to manipulate the lens. Fully retracted, the lens will take a wide shot. When fully extended, it will bring in a distant object. Most digital cameras have at least a 3x zoom.