I'm buying a digital camera and I looked them up online. It had 3 different kinds of zooms and I don't know the difference between them. Help? The optical zoom is what's important. That's how much your lens will actually telescope to zoom in. Digital zoom just enlarges the pixels, and you can't see any more detail. It can be useful, especially in a camera with more megapixels, but I don't recommend going by it. The combined zoom is both of them multiplied. For example, my camera has 10x optical and 4x digital, so my combined zoom is 40x.
Hope that helps. As phoenix said, the optical zoom is the important part. As a matter of fact, it is the only one that matters. Digital zoom is the same thing you could do on your computer with image editing software and just increase the size of the picture. So, when buying a camera, look only at the optical zoom... everything else is just good marketing strategy. 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...
4xDigitalFull: http://www.flickr.com/photos/7189769@N04...
3xOpticalCrop: http://www.flickr.com/photos/7189769@N04...
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. |
