A video camera is used to convert an image into an electrical signal that can form a picture on a TELEVISION screen or be recorded on video TAPE. Light enters the camera through a LENS. This bends the light rays together so that they form a sharp image on a light-sensitive plate called a target. The target is nor- mally charged up to about 30 volts. When light falls on it, the voltage leaks away. A brightly lit part of the target may fall to zero volts. The pick-up tube produces an ELECTRON beam that scans across the target. It restores each part of the target to its fully charged state. The bright parts of the target require greater charging than the darker parts. This charging current forms the video signal from the camera Although many cameras used in television studios still have pick-up tubes, most home video cameras and cam corders (a camcorder is a combined camera and re- corder) use a different light sensor called a charge coupled device or CCD. This SEMICONDUCTOR device is much smaller than a pick-up tube, is less fragile than the glass tube and it is not damaged by exposure to very bright light as the pick-up tube can be. See also VIDEO RECORDER.