What's the difference between optical zoom and digital zoom on a digital camera. Which do I most likely want?

Answer 1

Optical zoom is good and digital zoom sucks. Optical zoom is "real" zoom done with the camera lens. Digital zoom is really just a way to enlarge pixels and degrade the image. Ignore it completely when you are comparing cameras.

Here are three sample pictures taken with my Canon Powershot SD900, which is a 10.0 megapixel camera. All three pictures are taken with the optical zoom maxed out at 3X or 23.1 mm, which is the equivalent of 111.6 mm after calculating for the lens crop factor. There is no image processing at all done with any of these pictures. All were taken using the self-timer to (hopefully) eliminate camera shake as the camera sat on the top of my car. (Okay, I'll use a tripod next time, but I think they are pretty sharp images.) Please click on "View All Sizes" and then view each image at the largest size available, which should be 3648 x 2736 pixels. The first picture (3xOpticalFull) is the full frame image at 3x optical zoom, or 111 mm. The second picture (4xDigitalFull) is the result of zooming out the additional 4x in digital zoom, for an equivalent of 444 mm. The third picture (3xOpticalCrop) is actually a cropped version of the original image, maintaining the full pixel dimension. In other words, I accomplished the "digital zoom" entirely in the computer and not in the camera. If you compare the full-sized images, I think it is immediately obvious that the third picture is far superior in any aspect that you care to examine. I think it is much sharper (Check the tower and the antenna up near the top of the frame.), has better color, and less digital noise and artifact (Check the plain sky and the shadows on the building.). These images are all tagged "digital zoom."

3xOpticalFull: http://www.flickr.com/photos/7189769@N04/459603923/
4xDigitalFull: http://www.flickr.com/photos/7189769@N04/459603931/
3xOpticalCrop: http://www.flickr.com/photos/7189769@N04/459603939/

In other words, please ignore any claims of superiority based on "digital zoom" when you choose your camera. It is only "in camera cropping" and it is not anywhere near as good as "in computer cropping." Any attempts at cropping a digitally-zoomed picture will be a waste of time.

Answer 2

Short Answer: Digital zoom is absolute garbage. You want optical zoom. Long Answer: Optical zoom refers to when the lens moves and adjusts the zoom length. If you've ever seen one of those huge pro camera lenses that extend a lot, that is optical zoom. It works the same way in all cameras, but the lenses aren't that long so you can't see them moving. In sum, optical zoom is the camera physically adjusting the lens so you can see farther with the camera. Digital zoom, on the other hand, is the computer in the camera zooming in on whatever you're looking at. There's no hardware involved at all. Think about when you zoom in on a picture on your computer. The more you zoom in, the worse the picture works. This is exactly what the camera does with digital zoom. While it gets you a lot closer, the quality gets worse, unlike with optical zoom, where zooming does not harm quality. In sum, digital zoom on your camera is the same as magnifying on your computer. If you zoom in 25x on a 12 megapixel camera, the picture quality will be absolutely terrible. My suggestion is to ignore digital zoom completely when looking for a camera. It doesn't help at all. As for the concert, will it be dark there? If it will, you will not have good quality pictures. The darker a place is, the longer the camera needs to absorb light to take a good picture. If it's well lit or in the daytime outside, it should be fine.

Answer 3

Optical zoom uses the lens to zoom. Digital zoom just zooms in on the picture file created on your camera. NEVER use digital zoom. You would be better off to zoom and crop the picture in a photo-shop type program (as this is essentially what digital zoom does).

Using digital zoom if you make the object appear twice as big you will have one quarter the picture quality.

Answer 4

With optical, you are actually getting closer to the object, it's actually zooming in. With digital, it just increases the size of the pixels, so the more you zoom with digital the more blurry the picture will get. You will definitely want optical zoom, at least 3x.

Answer 5

The only real zoom is optical. Digital is fictional. Get what you want out of Optical and ignore digital.

Answer 6

you want a camera with a higher optical zoom. Optical zoom uses the lens of the camera to bring the subject closer, kinda like when you use binoculars.

digital zoom is the same like the zoom you use on a computer, when you zoom in on a photo. the photo looks more pixelated, and you lose out on quality.

Answer 7

You want optical zoom, trust me. Digital zoom sucks.

Answer 8

optical zoom is real, digital is just an enlargement

turn digital zoom off, if you must enlarge do it on the computer if you dont like it you can go back, shot it in the camera enlarged you cant go back

Answer 9

Digital zoom uses pixels to forn the picture and if you zoom in to far you can see the pixels but optical zoom doesnt use pixels therefore when you zoom in to far the pic just blurs.

Answer 10

Just as a counterpoint, too much optical zoom can cause problems too. Problems like edge blur, purple fringe, and slow times focusing times can plague the super-zooms.

Most compact digitals have 3x or 4x and that is about all you can hope for. If they have more than that, check the reviews carefully!

www.dpreview.com is a good web site for reviews.