video camera

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.

Technology

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.

Studio cameras

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.

ENG cameras

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:

  • They are bigger, and usually have a shoulder stock for stabilizing on the cameraman's shoulder
  • They use 3 CCDs instead of one (as is common in digital still cameras and consumer equipment), one for each primary color
  • They have removable/swappable lenses
  • All settings like white balance, focus, and iris can be manually adjusted, and automatics can be completely disabled
  • If possible, these functions will be even adjustable mechanically (especially focus and iris), not by passing signals to an actuator or digitally dampening the video signal.
  • They will have professional connectors - BNC for video and XLR for audio
  • A complete timecode section will be available, and multiple cameras can be timecode-synchronized with a cable
  • "Bars and tone" will be available in-camera (the bars are SMPTE (Society of Motion Picture and Television Engineers) Bars similar to those seen on television when a station goes off the air, the tone is a test audio tone)
  • Finally, they will often use a professional medium like some variant of Betacam or DVCPRO.

Dock cameras

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.

History

  • 1926 to 1933 "Cameras" were a type of flying spot scanner using mechanical disk.
  • 1936 saw the arrival of RCA's iconoscope camera.
  • 1946 RCA's TK-10 studio camera used 3" IO - Image Orthicon Tube with a 4 lens turret. The RCA TK-30 (1946) was widely used as a Field Camera.
  • The 1948 Dumont Marconi MK IV was an Image Orthicon Camera. Marconi's first camera was shown in 1938. - link to MK IV EMI cameras from the UK, were used in the US in the early 1960s, like the EMI 203/4. - Ext. link Later in the 60s the EMI 2000 an EMI 2001.
  • In 1950 the arrival of the Vidicon camera tube made smaller cameras possible. 1952 saw the first Walkie-Lookie "portable cameras". Image Orthicon tubes were still used till the arrival of the Plumbicon.
  • The RCA TK-40 is considered to be the first color television camera for broadcasts in 1953. RCA continued it lead in the high-end camera market till the (1978) TK-47, last of the high-end tub cameras. - Link to History of TV Books online
  • Ikegami introduced the first truly portable hand-held TV camera in 1962.
  • Philips' line of Norelco cameras were also very popular like models PC-60 (1965), PC-70 (1967) and PCP-90 (1968 Handheld). Philips/BTS-Broadcast Television Systems Inc. later came out with an LDK line of camera, like its last high end tube camera the LDK 6 (1982). Philips invented the Plumbicon pick up Video camera tube in 1965, that gave tube cameras a cleaner picture. BTS introduced its first HandHeld Frame transfer CCD- Charge-coupled device-CCD camera the LDK90 in 1987.
  • Bosch Fernseh marketed a line of high end cameras (KCU, KCN, KCP, KCK) in the US ending with the tube camera KCK-40 (1978). Image Transform (in Universal City) used specially modified 24 frame KCK-40 for their "Image Vision" system. This had a 10 MHz bandwidth twice NTSC resolution. This was a custom pre HDTV video System. At its peak this system was used to make "Monty Python Live at the Hollywood Bowl" in 1982. This was the first major high-definition analog wideband videotape-to-film post production using a Film recorder for Film out.

See also

References

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