- The ability to zoom in is obviously useful if you want to film something that is far away, but you should be aware that modern camcorders typically offer both optical zoom and digital zoom. Optical zoom enlarges the image on the charge coupled device, or CCD -- the light-sensitive semiconductor chip a camcorder uses to convert light images into electrical signals -- in the same, traditional way as a telescope or a pair of binoculars enlarges an image.
- Alternatively, you can think of optical zoom as varying the field of view. For any given CCD sensor, a larger image means a smaller field of view and vice versa. Optically, the field of view is almost proportional to the effective focal length of the optical system and the zoom ratio is defined as the ratio between the maximum and minimum effective focal length.
- Digital zoom does not involve physical movement of the camcorder lens and is achieved by cutting off, or cropping, unwanted areas of an image on the CCD and enlarging the remaining image to fill the whole screen. Digital zoom involves redrawing the picture elements, or "pixels," in an image, which typically results in a loss of sharpness and/or resolution in the final image. Digital zoom is less preferable than optical zoom, so you should look for a camcorder with at least 10x optical zoom, regardless of its digital zoom capabilities.
- Even if you use optical rather than digital zoom, the closer you zoom in to your subject the shakier your footage is likely to be. Any vibration of the camcorder, however small, is also magnified by 10 times -- or whatever level of optical zoom you are using -- so if zooming in is important to you, you might like to consider a monopod, bipod or tripod to support your camcorder. Focusing, too, can be an issue when you're zoomed in. The more you zoom in, the shorter the distance from the camera -- otherwise known as the depth of field -- that can be kept in focus simultaneously.
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