- Cameras and camcorders use zoom lenses to magnify objects in front of them. Your basic point-and-shoot digital camera can offer as little as a 3x magnification, while your advanced camcorder can magnify an object up to 60x or more. These lenses are great for bringing distant subjects up close and personal.
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Most lenses are composed of pieces of shaped glass called elements. Their job is to capture light, focus it and direct it toward the image sensor of a camera or camcorder.
An optical zoom lens contains a tiny motor that will move these elements back and forth to achieve magnification. What this motor does is change the lens' focal length -- that is, it alters the distance between the center of the lens and the image sensor.
As the focal length increases (i.e. as the center point of the lens gets further away from the sensor) you will bring faraway objects closer. As you decrease the focal length, you will achieve a wider field of view. -
The optical zoom rating of a camcorder or camera (measured as a factor of "x") should be considered its true zoom capability. A digital zoom is not the same. It's merely a computer gimmick that crops the photo or video in front of the lens and magnifies the remaining pixels to give you the impression that you've focused closer on a subject. In fact, all you've done is decreased the resolution of the photo or video in front of you.
Some vendors will try to be clever and advertise a "total zoom" capability that includes both the optical and digital zoom ratings combined. Again, don't be fooled. Only the optical zoom rating gives you a clear sense of how close you'll be able to get to your subject.
