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Professional video camera |
A professional video camera (often called a television camera even though the use has spread) is a high-end device for recording 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 camcorders) used for ENG and EFP image acquisition, and 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.
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It is common for professional cameras to split the incoming light into the three primary colors that humans are able to see, feeding each color into a separate pickup tube (in older cameras), charge-coupled device (CCD) and Active pixel sensor (CMOS image sensor). Some high-end consumer cameras also do this, producing a higher-quality image than is normally possible with just a single video pickup. Newer CCD and CMOS (solid state) image sensor ICs provide much better image pickup qualities as compared to older vacuum pickup tubes. Vacuum pickup tubes suffered from drift and alignment problems due to temperature variations and sensitivity changes due to aging. Solid state image sensors do not exhibit the same degree of drift and aging problems, which in quality sensor designs are either so small as to be negligible or automatically compensated. Solid state sensors are generally more sensitive to light than vacuum tubes although in extremely low light conditions this is debatable for some applications. Some disadvantages of solid state sensors are that their resolution is fixed by design whereas tube resolution can be changed by changing the scanning, individual pixels of solid state sensors may fail creating a steady white or black dot on the image at that defective pixel location and solid state sensors may delay the output video signal for one or more frames, thereby causing the televised video to be delayed relative to the audio thus adding to audio to video synchronization problems.
Most 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 studio setup is controlled by a device known as CCU (camera control unit), to which they are connected via an optical, Triax or Multicore cable. The camera control unit along with other equipments is installed in the production control room often known as Gallery of the television studio. When used outside a studio, they are often on tracks. Initial models used analog technology, but digital models are becoming more common. Some studio cameras are light and small enough to be taken off the pedestal and used on a cameraman's shoulder, but they still have no recorder of their own and are cable-bound.
Often used in independent films, ENG video cameras are similar to consumer camcorders, and indeed the dividing line between them is somewhat blurry, but a few differences are generally notable:
Some manufacturers build camera heads, which only contain the optical array, the CCD sensors and the video coder, and can be used with a studio adapter for connection to a CCU 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 electronic field production and low-budget studio use, because they tend to be smaller, lighter, and less expensive than most studio cameras.
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