In CCTV, a 16-millimeter lens is normal, although wide angle and telephoto lenses are available. A variety of filters are available, with neutral density and infrared filters being the most useful. In general, a lower f-stop is better. Lens controllers are available that allow users to control the focus, zoom, and iris aperture from a distance. CCTV cameras may be tube or solid state. Solid-state cameras are available in charge-injected and charge-coupled device forms and may be preferable to tube cameras in that they do not suffer from image lag, burn, blooming, or interference from external radio frequency fields. Three parts of the CCTV system require wiring: video, power, and control circuits. The two major types of able used in wiring, coaxial and fiber optic, each have their own advantages and disadvantages. Among high technology CCTV options available are quad-split screens that accept and display up to four video inputs on a single screen, slow-scan devices, motion detectors, time-lapse recorders, and programming and storage options (videocassette, floppy disks, and laser disks). Some companies offer color options, and systems using artificial intelligence will soon be available. Illustrations.