Video camera

From Wikipedia, the free encyclopedia

A video camera is a camera used for electronic motion picture acquisition, initially developed by the television industry but now common in other applications as well. The earliest video cameras were those of John Logie Baird, based on the electromechanical Nipkow disk and used by the BBC in experimental broadcasts through the 1930s. All-electronic designs based on the cathode ray tube, such as Vladimir Zworykin's Iconoscope and Philo T. Farnsworth's Image Dissector, supplanted the Baird system by the 1940s and remained in wide use until the 1980s, when cameras based on solid-state image sensors such as CCDs (and later CMOS active pixel sensors) eliminated common problems with tube technologies such as burn-in and made digital video workflow practical.

Video cameras are used primarily in two modes. The first, characteristic of much early television, is what might be called a live broadcast, where the camera feeds real time images directly to a screen for immediate observation; in addition to live television production, such usage is characteristic of security and military/tactical operations where surreptitious or remote viewing is required. The second is to have the images recorded to a storage device for archiving or further processing; videotape is traditional for this purpose, but optical disc media, hard disk, and flash memory are all used as well.

Modern video cameras have numerous designs and uses, not all of which resemble the early television cameras.

• Professional video cameras, such as those used in television and sometimes film production; these may be studio-based or mobile.
• Camcorders, which combine a camera and a VCR or other recording device in one unit; these are mobile, and are widely used for television production, home movies, electronic news gathering (including citizen journalism), and similar applications.
• Closed-circuit television cameras, generally used for security and surveillance purposes.
• Webcams, which provide digital video feeds for computer systems and networks; such cameras are often extremely small, even smaller than CCTV security cameras. These cameras are sometimes incorporated directly into computer or communications hardware, particularly mobile phones, PDAs, and some models of laptop computer.
• Special systems, like those used for scientific research, e.g. on board a satellite or a spaceprobe.

[edit] See also

• Video camera tube