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 image burn-in and made digital video workflow practical.
Video cameras are used primarily in two modes. The first, characteristic of much early broadcasting, is live television, where the camera feeds real time images directly to a screen for immediate observation.
A few cameras still serve live television production, but most live connections are for security, military/tactical, and industrial operations where surreptitious or remote viewing is required.
In the second mode the images are recorded to a storage device for archiving or further processing; for many years, videotape was the primary format used for this purpose, but optical disc media, hard disk, and flash memory in tapeless camcorders are all increasingly used. Recorded video is used in television and film production, and more often surveillance and monitoring tasks where unattended recording of a situation is required for later analysis.
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