A video camera is an optical device that captures videos, as opposed to a movie camera, which records images on film. Video cameras were originally designed for the television industry, but they have subsequently been widely employed for a number of other applications.
Video cameras are used primarily in two ways. The first, typical of much early broadcasting, is live television, in which the camera broadcasts real-time images directly to a screen for immediate viewing. A few cameras continue to service live television production, while the majority of live connections are used for security, military/tactical, and industrial operations that require covert or remote monitoring. In the second mode, the photos are saved into a storage device for preservation or For many years, videotape was the primary format for this function, but it was gradually replaced by optical disc, hard disk, and finally flash memory. Recorded video is utilized in television production, as well as surveillance and monitoring duties that necessitate unattended recording of a scene for subsequent analysis.
Types and usage
Modern video cameras have a variety of forms and uses:
Professional video cameras, such as those used in television production, can be stationary in a television studio or movable in the case of electronic field production (EFP). Such cameras typically provide highly fine-grained human control for the camera operator, frequently at the expense of automated operation. They typically use three sensors to individually record red, green, and blue.
Camcorders use a camera and a VCR or other recording device in one unit; these are portable and were commonly used for television production, home movies, electronic news gathering (ENG) (including citizen journalism), and other purposes. Since the shift to digital video cameras, most cameras now feature built-in recording media and hence function as camcorders. Action cameras frequently provide 360° recording capabilities.
Closed-circuit television (CCTV) typically employs pan-tilt-zoom cameras (PTZ) for security, surveillance, and/or monitoring. Such cameras are intended to be small, easily concealed, and self-contained; those used in industrial or scientific settings are frequently intended for use in environments that are normally inaccessible or uncomfortable for humans, and are thus hardened for such hostile environments (e.g., radiation, high heat, or toxic chemical exposure).
Webcams are Video cameras that send live video feeds to a computer.
Many smartphones include built-in video cameras, and even high-end smartphones can record video in 4K resolution.
Special camera systems are employed in scientific study, such as onboard a satellite or space probe, artificial intelligence and robotics research, and medicinal applications. Such cameras are frequently tuned for non-visible radiation such as infrared (for night vision and heat sensing) or X-ray (for medical and video astronomy applications).
History
The first video cameras were built on the mechanical Nipkow disk and used in experimental transmissions from the 1910s to the 1930s. By the 1930s, all-electronic versions based on the video camera tube had overtaken the Nipkow system, including Vladimir Zworykin’s Iconoscope and Philo Farnsworth’s image dissector. They remained Cameras based on solid-state image sensors such as the charge-coupled device (CCD) and later the CMOS active-pixel sensor (CMOS sensor) eliminated common problems with tube technologies such as image burn-in and streaking, making digital video workflow practical, because the sensor’s output is digital and does not require analog conversion.
Solid-state image sensors are based on metal-oxide-semiconductor (MOS) technology, which dates back to the creation of the MOSFET (MOS field-effect transistor) at Bell Labs in 1959.[2] This resulted in the creation of semiconductor image sensors, such as the CCD and later the CMOS active-pixel sensor.[1] The first semiconductor image sensor was the charge-coupled device, developed at Bell Labs in 1969[3] and based on MOS capacitor technology.[1] The In 1985, Olympus invented the NMOS active-pixel sensor. [4][5][6] This led to the creation of the CMOS active-pixel sensor at NASA’s Jet Propulsion Laboratory in 1993.[7][5]
Advances in video compression also enabled workable digital video cameras, as uncompressed video had impractically high memory and bandwidth needs.[8] The most notable compression algorithm in this area is the discrete cosine transform (DCT), a lossy compression technique initially described in 1972.[10] DCT-based video compression methods, such as the H.26x and MPEG video coding standards, made practical digital video cameras possible beginning in 1988.[9]
The switch to digital television boosted demand for digital video cameras. By the early 21st century, the majority of video cameras were digital.
With the advent of With digital video capture, the distinction between professional video cameras and movie cameras has vanished because the intermittent mechanism is the same. Professional video cameras are now defined as mid-range cameras used solely for television and other purposes (excluding movies).
Recording Media
Early video could not be directly recorded.[11] In 1927, John Logie Baird’s disc-based Phonovision was the first partially successful attempt to directly record video.[11] The disks were unplayable with the technology at the time, but later developments enabled the footage to be recovered in the 1980s.[11] The earliest experiments with utilizing tape to record a television stream were conducted in 1951.[12] Ampex manufactured the first commercially deployed technology, Quadruplex videotape, in 1956.[12] Two years later, Ampex launched a system of recording color video.[12] The earliest recording systems designed to be mobile (and hence useful outside the studio) were the Portapak systems, which debuted with the Sony DV-2400 in 1967.[13] This was followed in 1981 by the Betacam system, which integrated the tape recorder inside the camera to create a camcorder.[13]
Lens mounts.
While some video cameras have built-in lenses, others employ interchangeable lenses attached to a variety of mounts. Some, such as the Panavision PV and Arri PL, are meant for cinema cameras, but others, such as the Canon EF and Sony E, are for still photography.[14] For applications like as CCTV, there are additional mounts available, such as the S-mount.
