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Zooming with lens, a winner
Q: What is the difference between optical and digital zoom, and what are the limits of digital zoom?
-John B., Orlando Florida
A: The answer is probably what you think it is. A digital zoom simply enlarges the pixels in the image; an
optical zoom uses the lenses of the camera. The limit to digital zoom is whatever is built into the camera. The
ultimate limit is enlarging until you look at one pixel.
Above: [Imaging Resource] Fuji FinePix 4900 Zoom digital camera
It's cheap but useful. You can zoom digitally with your computer or in some cameras. Common zooms are 2.5X (magnification) for
optical zoom and 4X for digital zoom. When the optical runs out, the digital takes over. Optical zoom is expensive since it requires
good lenses.
"While 'digital' often means 'better,' in this case optical zoom is the winner," says Dave Etchells of Imaging Resource Digital Camera
Database. Digital zoom enlarges the pixels--stretching the image and making it softer (more blurry) in the process. Optical zoom,
however, enlarges the image the camera's sensor actually sees with no loss of detail.
Digital zoom is handy for email or web use, Etchells says. "If you're interested in making prints from your digital pictures, though, the
more costly optical zoom is the hands-down winner."
(Answered by April Holladay, science correspondent, November 14, 2001)
Further Surfing:
Imaging Resource: Getting started
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