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A professional video camera (often called a television camera even though the use has spread beyond television) is a high-end device for creating electronic moving images (as opposed to a movie camera, that records the images on film). Originally developed for use in television studios, they are now commonly used for corporate and educational videos, music videos, and direct-to-video movies.
There are two types of professional video cameras: High end portable, recording cameras (essentially, high-end tapeless camcorders) used for Electronic news gathering (ENG) and Electronic field production (EFP) image acquisition, and television studio cameras which lack the recording capability of a camcorder, and are often fixed on studio pedestals. Portable professional cameras are generally much larger than consumer cameras and are designed to be carried on the shoulder.
Professional television camera history has two main lines: the gradual shrinking of the camera as it became more versatile and self contained; and a progression of sensors from large insensitive tubes to smaller, much more sensitive tubes and finally to very small, very sensitive solid state charge-coupled device (CCD) and active pixel sensor (CMOS) imagers. Betacam cameras that contained their own recording mechanisms did not appear until the early 1980s.
At the beginning, these cameras were very large devices, almost always in two sections. The camera section held the lens and tube pre-amps and other necessary electronics, and was connected with a large diameter multicore cable to the rest of the camera electronics, usually mounted in a rack. The rack would be in a separate room in the studio, or in a remote truck. The camera head could not generate a video picture signal on its own. The video signal was output from the rack unit to the rest of the studio for switching and transmission. By the fifties, electronic miniaturization had progressed to the point where some monochrome cameras could operate stand alone and even be handheld. But the studio configuration remained, with the large cable bundle transmitting the signals back to the CCU (Camera control unit). The CCU in turn was used to align and operate the camera's functions, such as exposure, system timing, and video and black levels.
The first color cameras (1950s in the US, early 1960s in Europe), notably the RCA TK-40/41 series, were much more complex with their three (and in some models even four) pickup tubes, and the size and weight drastically increased. Handheld color cameras did not come into general use until the early 1970s, and the first ones were two pieces, a camera head shoulder unit that held the lens and pickup tube section, and a backpack unit. The Ikegami HL-33 was the first of this type, but was followed up by one piece cameras. These one piece cameras, (The HL-77 from Ikegami and the TK76 from RCA) made possible, (in combination with portable 3/4" U-matic VCRs) the introduction of the Electronic news-gathering (ENG) camera, which very rapidly replaced the 16mm film cameras that had been the dominant method for capturing news events. This established the standard operation in the field of a two person news crew, one operating the camera, and one carrying the shoulder strapped U-matic recorder and a boom microphone. The control layout (often called "form factor") for the camera's most important functions was also established with these cameras, and continues to define an ENG camera to this day.
In the early 80s, the first cameras with an on board recorder were brought to the market. The more successful of these used the Betacam recording system. At first these cameras used pickup tubes, and the recorders were of the removable type. Models with solid state CCD imagers came on the scene in the mid-80s. These brought multiple benefits. They were much more stable and less prone to drift than tube cameras, and didn't require a warm up or calibration time at the beginning of the day. They also were not prone to image burn in or lag caused by very bright light sources in the frame. The early models did not have the resolution or color quality of their tube counterparts, but successive models quickly pulled ahead of tube technology. Eventually, cameras with the recorder permanently mated to the camera head became the norm for ENG.
Studio camera technology did not stand still during this period. The camera electronics shrank, and CCD imagers replaced the pickup tubes. The thick multi-core cables connecting the camera head to the CCU were replaced in the late seventies with triax connections, a slender video cable that carried multiple video signals, intercom audio, and control circuits, and could be run for a mile or more. As the camera innards shrunk, the electronics no longer dictated the size of the enclosure. But the box shape remained, as it was necessary to hold the large studio lenses, teleprompters, electronic viewfinder (EVF), and other paraphernalia needed for studio and sports production. Electronic Field Production cameras were often mounted in studio configurations inside a mounting cage. This cage supported the additional studio accessories.
In the late 90s, as HDTV broadcasting commenced, HDTV cameras suitable for news and general purpose work were introduced. Though they delivered much better image quality, their overall operation was identical to their standard definition predecessors. New methods of recording for ENG cameras were introduced to supplant video tape, tapeless cameras. Ikegami and Avid introduced EditCam in 1996, based on interchangeable hard drives. Panasonic introduced P2 cameras. These recorded a DVCPro signal on interchangeable flash memory card media. Several other data storage device recording systems were introduced, notably XDCAM from Sony, and as of 2009, it remains to be seen what will become the predominant method of camera media for professional use in the 2010s. Sony also introduced SxS (S-by-S), a flash memory standard compliant to the Sony and Sandisk-created ExpressCard standard.
Most professional cameras utilize an optical prism block directly behind the lens. This prism block (a trichroic assembly comprising two dichroic prisms) separates the image into the three primary colors, red, green, and blue, directing each color into a separate charge-coupled device (CCD) or Active pixel sensor (CMOS image sensor) mounted to the face of each prism. Some high-end consumer cameras also do this, producing a higher-resolution image, with better color fidelity than is normally possible with just a single video pickup.
In both single sensor and triple sensor designs, the weak signal created by the sensors is amplified before being encoded into analog signals for use by the viewfinder and monitor outputs, and also encoded into digital signals for transmission and recording. The analog outputs are normally in the form of either a composite video signal, which combines the color and luminance information to a single output; or an R-Y B-Y Y component video output through three separate connectors.
Most television studio cameras stand on the floor, usually with pneumatic or hydraulic mechanisms called pedestals to adjust the height, and are usually on wheels. Any video camera when used along with other video cameras in a multiple-camera setup is controlled by a device known as CCU (camera control unit), to which they are connected via a Triax, Fibre Optic or the almost obsolete multicore cable. The CCU along with genlock and other equipment is installed in the production control room (PCR) often known as the Gallery of the television studio. When used outside a formal television studio in outside broadcasting (OB), they are often on tripods that may or may not have wheels (depending on the model of the tripod). Initial models used analog technology, but are now obsolete, supplanted by digital models. Studio cameras are light and small enough to be taken off the pedestal and the lens changed to a smaller size to be used on a Multiple-camera setup's shoulder, but they still have no recorder of their own and are cable-bound. Cameras can be mounted on a tripod, a dolly or a crane, thus making the cameras much more versatile than previous generations of studio cameras. These cameras have a tally light, a small signal-lamp used that indicates, for the benefit of those being filmed as well as the camera operator, that the camera is 'live' - i.e. its signal is being used for the 'main program' at that moment.
Though by definition, ENG (Electronic News Gathering) video cameras were originally designed for use by news camera operators, these have become the dominant style of professional video camera for most video productions, from dramas to documentaries, from music videos to corporate video training. While they have some similarities to the smaller consumer camcorder, they differ in several regards:
Electronic Field Production cameras are similar to studio cameras in that they are used primarily in multiple camera switched configurations, but outside the studio environment, for concerts, sports and live news coverage of special events. These versatile cameras can be carried on the shoulder, or mounted on camera pedestals and cranes, with the large, very long focal length zoom lenses made for studio camera mounting. These cameras have no recording ability on their own, and transmit their signals back to the broadcast truck through a triax, fiber optic or the virtually obsolete multicore cable.
Some manufacturers build camera heads, which only contain the optical block, the CCD sensors and the video encoder, and can be used with a studio adapter for connection to a CCU in EFP mode, or various dock recorders for direct recording in the preferred format, making them very versatile. However, this versatility leads to greater size and weight. They are favored for EFP and low-budget studio use, because they tend to be smaller, lighter, and less expensive than most studio cameras.
Remote cameras are typically very small camera heads designed to be operated by remote control. Despite their small size, they are often capable of performance close to that of the larger ENG and EFP types.
"Lipstick cameras" are so called because the lens and sensor block combined are similar in size and appearance to a lipstick container. These are either hard mounted in a small location, such as a race car, or on the end of a boom pole. The sensor block and lens are separated from the rest of the camera electronics by a long thin multi conductor cable. The camera settings are manipulated from this box, while the lens settings are normally set when the camera is mounted in place.
Block cameras are so called because the camera head is a small block, often smaller than the lens itself. Some block cameras are completely self contained, while others only contain the sensor block and its pre-amps, thus requiring connection to a separate camera control unit in order to operate. All the functions of the camera can be controlled from a distance, and often there is a facility for controlling the lens focus and zoom as well. These cameras are mounted on pan and tilt heads, and may be placed in a stationary position, such as atop a pole or tower, in a corner of a broadcast booth, or behind a basketball hoop. They can also be placed on robotic dollies, at the end of camera booms and cranes, or "flown" in a cable supported harness, as shown in the illustration.
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