Main Page | See live article | Alphabetical index Main Page | See live article | Alphabetical index A zoom lens is a mechanical assembly of lenses whose focal length can be changed. Zoom lenses are mainly used in cameras and binoculars to increase or decrease the size of the image captured by the device. Some digital cameras use electronic manipulation of the image to increase or decrease its size. This is commonly known as digital zoom and results in a much lower quality image than mechanical zooming. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.