- Worldstart's Tech Tips And Computer Help - http://www.worldstart.com -

Beware The Digital Zoom

Posted By On November 17, 2004 @ 9:38 PM In Digital Photography | No Comments

Beware The Digital Zoom!

Here’s the story behind this week’s exciting digital imaging tip:

My wife just got a new digital camera—her first actually. We found a simple, easy to use little Kodak and all seemed well, at first.

You see, this camera features both an optical and digital zoom. And that’s where the trouble starts.

My wife zooms in on our 3-year-old son and then decides to keep zooming with the digital zoom! I know, I couldn’t believe it either.

As soon as I saw what was happening, I yelled to her, “WAIT! Don’t trip that shutter!”

At this point everything seemed to move in slow motion. Like Spider Man I leapt into the air and grabbed the camera from her trembling fingers. However, unlike Spider Man, I don’t have any of that web stuff, so I smacked into the wall like a myopic bird smacking into a windowpane. Ahh, but the image was saved!

OK, maybe I made some of that up, but here’s why I mention it:

Optical zooms are good, digital ones are bad.

You see, optical zooms use the lens—glass optics and such—to magnify the subject. On the other hand, digital zooms use software trickery.

When you “zoom” in with a digital zoom, two things happen. First, the camera crops the image, making it look closer. OK, that’s not so bad. The second thing that happens is the camera “adds” extra pixels to keep the image size to what it’s supposed to be.

For example, let’s say you have a 4MP camera. You use the digital zoom to crop in closer. The camera is set to record images at 4MP, but after the crop, the image is only 2MP. So, the camera “makes up” pixels to bring the 2MP image up to 4MP. The image loses quality like crazy.

Turns out you’d have been better off just taking it at the end of your optical zoom and cropping. Sure you couldn’t blow the picture up as much, but at least it would have been a good quality image.

That said, a little touch of digital zoom won’t hurt things too badly. Stay under 1X and the results aren’t too bad. From there, I personally don’t like the quality you typically get, but I suppose that all depends on how picky you are.

Suffice to say, the less digital zoom you use, the better your images will be :-)

~ Steve


Article printed from Worldstart's Tech Tips And Computer Help: http://www.worldstart.com

URL to article: http://www.worldstart.com/beware-the-digital-zoom/