What Is Optical Zoom?

by Fred Decker
With optical zoom, higher power is better.

With optical zoom, higher power is better.

With traditional film-based cameras, your ability to enlarge or "zoom in" on a scene was determined entirely by the lenses on your camera. With modern digital cameras, that's no longer the case. Because the image is recorded digitally, it can also be zoomed digitally, just like you can enlarge a Web page on your computer's screen. However, the power of your camera's lens -- now called "optical zoom" -- remains a crucial factor in picture quality.

More Is Better

Most digital cameras give two numbers for their zooming ability -- one for optical zoom and one for digital zoom. The optical zoom is the more important of the two, because it determines the quality of the original image. A camera with 20X optical zoom can get much closer to its subject than a camera with a 10X optical zoom. You can magnify the 10X image with digital zoom to give a comparable appearance, but the resolution will suffer. If you later need to enlarge the image for printing, its quality will be noticeably inferior, and it will lack sharpness and detail.

About the Author

Fred Decker is a trained chef and certified food-safety trainer. Decker wrote for the Saint John, New Brunswick Telegraph-Journal, and has been published in Canada's Hospitality and Foodservice magazine. He's held positions selling computers, insurance and mutual funds, and was educated at Memorial University of Newfoundland and the Northern Alberta Institute of Technology.

Photo Credits

  • photo_camera Purestock/Purestock/Getty Images