Optical vs Digital Zoom

On consumer digital cameras, the terms optical zoom and digital zoom are common. When shopping for a digital camera, ignore the digital zoom. What you should look for is the optical zoom capability, because what is captured using optical zoom is what the lens actually sees.
Digital zoom is basically using in-camera software to enlarge the center pixels in the photo, resulting in loss of detail and sharpness.

Some digital cameras use digital zoom exclusively, because they lack an optical zoom lens. On such cameras, the photo will be at its sharpest without using the digital zoom at all.
Other digital cameras have a combination of optical and digital zoom. On such cameras, I would turn off digital zoom entirely, and use only the optical zoom. This will ensure that I get sharp photos all the time.

	x 1	x 2	x 3
Optical Zoom
	Usually equivalent to a 35mm lens. Details in the photo are captured by the lens.	Usually equivalent to a 70mm lens. Details in the photo are captured by the lens.	Usually equivalent to a 105mm lens. Details in the photo are captured by the lens.
Digital Zoom
	Usually equivalent to a 35mm lens. Details in the photo are captured by the lens.	Camera adds pixels to make the photo larger. Details in the photo are artifically added via software in the camera.	Camera adds pixels to make the photo larger. Details in the photo are artifically addedvia software in the camera.