Thus far, here in our digital and DSLR camera shopping guide, we’ve tried to simplify and break down the distinctions between compact cams and SLRs. Now we want to tackle a few of the other general factors you should consider before you buy a digital camera. We’ll start with what has typically been one of the greatest areas of confusion for camera newbies – “optical zoom” versus “digital zoom.”
Optical zoom is the phrase used to indicate the strength of a given camera’s optical magnification (see Optical Zoom Lenses: Is Bigger Better for background info) and is the only phrase you should examine when speaking of zoom capabilities. “Digital zoom,” conversely, refers to the level of additional magnification achieved through a camera’s internal cropping abilities.
Thusly, digital zoom is a misleading misnomer. It does not zoom any further – it merely enlarges a section of the image you’ve already set up and framed. And most photographers know that if you enlarge a section of an image, you also enlarge all the pixels that make up that image and in so doing must take care not to enlarge it so far that you introduce noise.
A better idea? Magnify to the maximum optical zoom, take your shot, and crop later in a photo editing program. That way, you’ll keep your clean, but slightly more distant original, yet you can also experiment to see if you can crop a clean new image. But whatever you do, never, ever buy a camera because of its digital zoom numbers.