The camera control unit (CCU) is typically part of a

live television Live television is a television production broadcast in real-time, as events happen, in the present. In a secondary meaning, it may refer to streaming television where all viewers watch the same stream simultaneously, rather than watching vide ...

broadcast chain. It is responsible for powering the

professional video camera A professional video camera (often called a television camera even though its use has spread beyond television) is a high-end device for creating electronic moving images (as opposed to a movie camera, that earlier recorded the images on film). O ...

, handling signals sent over the camera cable to and from the camera, and can be used to control various camera parameters remotely.

History

Before cameras became self-contained units, broadcast cameras required vast racks of control units just to generate a usable picture. In outside broadcast production, these racks took up an entire section of the OB truck and were operated by a small team of skilled engineers. These vision engineers had two roles. Firstly, they set up the CCUs at the start of a production and ensured that the picture created was of broadcast quality. This process included a lengthy alignment process in which the vision engineer would work with the camera operator, to adjust the settings on both the actual camera and the CCU in tandem. During production, it was the vision engineers' job to operate the CCUs and control both the exposure and the colour balance. So skilled and labour-intensive was this role that each CCU required its own dedicated vision engineer.

Benefits

Modern cameras are typically more self-contained than their predecessors and many can operate without a CCU. Even when not required, a CCU can be of benefit for the following reasons: * In a system with a

multiple-camera setup The multiple-camera setup, multiple-camera mode of production, multi-camera or simply multicam is a method of filmmaking, television production and video production. Several cameras—either film cameras, film or professional video cameras—are ...

, the cameras can be matchedmade to look the same in terms of colour balance and picture intensity without having to ask

camera operator A camera operator, or depending on the context cameraman or camerawoman, is a professional operator of a film camera or video camera as part of a film crew. The term "cameraman" does not necessarily imply that a male is performing the task. ...

s to make an adjustment. * The camera operators are freed from the control of iris, black level and colour balance, leaving them free to concentrate on other aspects of camerawork such as blocking and image composition. * All signals that operate between the camera and CCU are carried in one

multicore cable A multicore cable is a type of electrical cable that combines multiple signals or power feeds into a single jacketed cable. The term is normally only used in relation to a cable that has more cores than commonly encountered. Not all cables with mu ...

triax Triaxial cable, often referred to as triax for short, is a type of electrical cable similar to coaxial cable, but with the addition of an extra layer of insulation and a second conducting sheath. Triax provides greater bandwidth and rejection of i ...

fiber optic An optical fiber, or optical fibre, is a flexible glass or plastic fiber that can transmit light from one end to the other. Such fibers find wide usage in fiber-optic communications, where they permit transmission over longer distances and at ...

cable.

Functions

A CCU is often used in conjunction with a remote-control panel (RCP), a

waveform monitor A waveform monitor is a special type of oscilloscope used in television production applications. It is typically used to measure and display the level, or voltage, of a video signal with respect to time. The level of a video signal usually corre ...

and a

vectorscope A vectorscope is a special type of oscilloscope used in both audio and video applications. Whereas an oscilloscope or waveform monitor normally displays a plot of signal vs. time, a vectorscope displays an X-Y plot of two signals, which can ...

to rack and match many cameras together remotely. Common adjustable parameters include: * Iris (see

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

) *

Color temperature Color temperature is a parameter describing the color of a visible light source by comparing it to the color of light emitted by an idealized opaque, non-reflective body. The temperature of the ideal emitter that matches the color most clos ...

filters *

Neutral density filter In photography and optics, a neutral-density filter, or ND filter, is a photographic filter, filter that reduces or modifies the intensity of all wavelengths, or colors, of light equally, giving no changes in hue of color rendition. It can be a ...

s *

Shutter speed In photography, shutter speed or exposure time is the length of time that the film or digital sensor inside the camera is exposed to light (that is, when the camera's shutter (photography), shutter is open) when taking a photograph. The am ...

Saturation Saturation, saturated, unsaturation or unsaturated may refer to: Chemistry *Saturated and unsaturated compounds, a classification of compounds related to their ability to resist addition reactions ** Degree of unsaturation **Saturated fat or satu ...

* Master gain * Master black (pedestal) * Black level trim (for red, green and blue components) * Gain trim (for red, green and blue components) In addition to these, there are usually options internally generating a

test card A test card, also known as a test pattern or start-up/closedown test, is a television test signal, typically broadcast at times when the transmitter is active but no program is being broadcast (often at sign-on and sign-off). Used since the ear ...

for testing, return feeds or talkback. For more complex productions, preset scene files can be recalled to quickly change the settings of the camera on the fly.

Connectivity

Broadcast cameras typically carry several signals over the camera cable in addition to the camera output itself. Typically, RGB signals are transmitted over the camera cable. The CCU will usually convert these to SDI, YUV or composite for interfacing to other video equipment - typically it will be connected to a

vision mixer A vision mixer is a device used to select between different live video sources and, in some cases, compositing live video sources together to create visual effects. In most of the world, both the equipment and its operator are called a visio ...

via a

video router A video router, also known as a video matrix switch or SDI router, is an electronic switch designed to route video signals from multiple input sources such as cameras, VT/DDR, computers and DVD players, to one or more display devices, such as ...

. Typical signals can be both

digital signal A digital signal is a signal that represents data as a sequence of discrete values; at any given time it can only take on, at most, one of a finite number of values. This contrasts with an analog signal, which represents continuous values; ...

and

analog signal An analog signal (American English) or analogue signal (British and Commonwealth English) is any continuous-time signal representing some other quantity, i.e., ''analogous'' to another quantity. For example, in an analog audio signal, the ins ...

s: * Video out (

Serial digital interface Serial digital interface (SDI) is a family of digital video Interface (computing), interfaces first standardized by SMPTE (The Society of Motion Picture and Television Engineers) in 1989. For example, ITU-R BT.656 and SMPTE 259M define digital ...

(SDI)) * Video out (

composite video Composite video, also known as CVBS (composite video baseband signal or color, video, blanking and sync), is an analog video format that combines image information—such as brightness (luminance), color (chrominance), and synchronization, int ...

) * Video out (

component video Component video is an analog video signal that has been split into two or more component channels. In popular use, it refers to a type of component analog video (CAV) information that is transmitted or stored as three separate signals. Compo ...

) * Audio out (

microphone A microphone, colloquially called a mic (), or mike, is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and publi ...

on board) * Video in (

genlock Genlock (generator locking) is a common technique where the video output of one source (or a specific reference signal from a signal generator) is used to synchronize other picture sources together. The aim in video applications is to ensure the ...

in the form of

color burst Colorburst is an analog and composite video signal generated by a video-signal generator used to keep the chrominance subcarrier synchronized in a color television signal. By synchronizing an oscillator with the colorburst at the back porc ...

) * Return video in (composite)typically for a

teleprompter A teleprompter, also known as an autocue, is a display device that prompts the person speaking with an electronic visual text of a speech or script. Using a teleprompter is similar to using cue cards. The screen is in front of, and usually bel ...

* Return video incarrying the output from the

Interruptible feedback Interruptible foldback (IFB), also known as interrupted foldback, interruptible feedback, or interrupt for broadcast, is a monitoring and cueing system used in television, filmmaking, video production, and radio broadcast for one-way communicati ...

Intercom An intercom, also called an intercommunication device, intercommunicator, or interphone, is a stand-alone voice communications system for use within a building, small collection of buildings or portably within a small coverage area, which funct ...

* Tally light trigger

References

External links