Camera control unit
 |
This article does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (December 2009) |
Contents |
[edit] Description
The Camera Control Unit is typically part of a live television broadcast "chain". It is responsible for powering the professional video camera, handling signals sent over the camera cable (multicore cable, triax or fiber) to and from the camera, and can be used to control various camera parameters such as iris remotely.
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.
[edit] Advantages over using independent cameras with automatic settings
-
- In a system with multiple-camera setup, the cameras can be "matched" - made to look the same in terms of colour balance and picture intensity without having to ask the camera operator to
-
- The camera operators are freed from the control of iris and black level - 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.
[edit] Scope of CCU functions
A CCU is often used in conjunction with a RCP (Remote Control Panel), a waveform monitor and a vectorscope to rack and match many cameras together remotely.
Common adjustable parameters include:
-
- Iris (see aperture)
- Color temperature filters
- Neutral density filter
- Master Black (pedestal)
- Black level trim (for red, green and blue components)
- Gain trim (for red, green and blue components)
- Master gain
In addition to these, there are usually options internally generating a test card for testing, return feeds or talkback. For more complex production, preset scene files can be recalled to quickly change the settings of the camera on the fly.
[edit] Connections to a CCU
Typical signals can be both digital signal and analog signals:
-
- Video out (Serial digital interface (SDI)
- Video out (composite video)
- Video out (component video)
- Audio out (microphone on board)
- Video in (genlock in the form of color burst)
- Return video in (composite)
- Return video in (vision mixer program out)
- Interruptible feedback Intercom
- Tally light trigger
