Whats The defference between optical zoom & Digital zoom?

-- terry Potter (tfpotter1@aol.com), February 23, 2000

Answers

A world of difference, a world.

-- The Masked Informer (green.lantern@dc.net), February 23, 2000.

Terry, Optical zoom is accomplished by shifting the elements within the lens. Digital zoom is done by manipulation of the digital data. It tends to be more noticeble in the output since you are expanding a small amount of data to fill a larger area. You should use digital zoom sparingly.

The down side to optical zoom is that as you magnify more, the speed of the lens decreases. To maintain the speed of the lens requires a larger, heavier, more expensive lens. So, as you zoom to longer focal lengths, your shutter time is going to increase.

-- Steve (milwaukeechrome@aol.com), February 23, 2000.

Digital zoom is the digital equivalent of cropping to the center of your picture and then blowing it up again. It's like taking a picture in your computer and going to the magnification/zoom function in one of the editing screen or going 640*480 to 1024*768. Do that with a picture, not just text and you will see a difference. It works, I guess OK, for pictures used on a computer monitor as the resolution used is small. It's pretty much unsatisfactory if you intend to blowup and print the pictures.

Optical is actually using the lens to change perspective and magnify/widen the view. You get a full frame worth of information at any setting. Most "zooms" stick to 3x to maintain performance across the range of the lens.

The trade-offs? Digital doesn't add any weight or cost to the camera and has some limited usefulness. It can be used to confuse the unwary. Optical zooms add cost, weight, size and require more manufacturing, engineering and complexity in the product.

At this point there are few interchangeable lens digitals in the consumer range (some would argue none) so if a camera doesn't have the optical zoom range to meet your needs, there is little you can do beyond a few add-on elements. They add a little wideness or magnification. You get what you pay for in these, not too much.

-- Craig Gillette (cgillette@thegrid.net), February 23, 2000.