Tally light
Encyclopedia
In a television studio
, a tally light is a small signal-lamp on a professional video camera
or monitor
. It is usually located just above the lens or on the so-called electronic viewfinder
(EVF) and communicatee, for the benefit of those in front of the camera 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. Tally (also known as the 'on-air' indication) lights are typically red, although some cameras and video switchers accept a preview tally signal, which is typically green.
In addition to the tally lights, an additional light called ISO is sometimes used. ISO is the abbreviation for "isolated", and indicates that the video signal is isolated and recorded separately. When the camera's signal isn't used for the main program, but is being recorded for later video editing
, a yellow light indicates to the operator
that the content might be used at a later stage. So, while he isn't on-air, the operator should try to prevent making sudden moves etc. The ISO content is typically used for b-roll
shots such as people's reactions when it's uncertain if, when, and how they will react.
For television productions with more than one camera in a multiple-camera setup
, the tally lights are generally illuminated automatically by a vision mixer
trigger that is fed to a tally breakout board and then to a special video router
designed for tally signals. The video switcher keeps track of which video sources are selected by the technical director
and output to the main program bus. A switch automatically closes the appropriate electrical contacts to create a circuit, this lights the tallys located in the camera control unit
s (CCU). If more than one camera is on-air simultaneously (as in the case of a dissolve
), during the duration of the transition the tally lights of both cameras will remain lit until transition completion.
With the increasing complexity of modern broadcast installations it is more common to find that a third party controller will manage the tally information along with mnemonic and crosspoint information from the video router
e.g a "TallyMan" unit from UK based company TSL.
Television studio
A television studio is an installation in which a video productions take place, either for the recording of live television to video tape, or for the acquisition of raw footage for post-production. The design of a studio is similar to, and derived from, movie studios, with a few amendments for the...
, a tally light is a small signal-lamp on a professional video camera
Professional video camera
A professional video camera is a high-end device for creating electronic moving images...
or monitor
Video monitor
A video monitor also called a broadcast monitor, broadcast reference monitor or just reference monitor, is a display device similar to a television set, used to monitor the output of a video-generating device, such as playout from a video server, IRD, video camera, VCR, or DVD player. It may or...
. It is usually located just above the lens or on the so-called electronic viewfinder
Electronic viewfinder
An electronic viewfinder or EVF is a viewfinder where the image captured by the lens is projected electronically onto a miniature display. The image on this display is used to assist in aiming the camera at the scene to be photographed.-Operation:...
(EVF) and communicatee, for the benefit of those in front of the camera as well as the camera operator
Camera operator
A camera operator or cameraman is a professional operator of a film or video camera. In filmmaking, the leading cameraman is usually called a cinematographer, while a cameraman in a video production may be known as a television camera operator, video camera operator, or videographer, depending on...
, that the camera is 'live' - i.e. its signal is being used for the 'main program' at that moment. Tally (also known as the 'on-air' indication) lights are typically red, although some cameras and video switchers accept a preview tally signal, which is typically green.
In addition to the tally lights, an additional light called ISO is sometimes used. ISO is the abbreviation for "isolated", and indicates that the video signal is isolated and recorded separately. When the camera's signal isn't used for the main program, but is being recorded for later video editing
Video editing
The term video editing can refer to:* Linear video editing, using video tape* Non-linear editing system , using computers with video editing software* Offline editing* Online editing...
, a yellow light indicates to the operator
Operator (profession)
An operator is a professional designation used in various industries, including broadcasting , computing, customer service, physics, and construction. Operators are day-to-day end users of systems, that may or may not be mission-critical, but are typically managed and maintained by technicians or...
that the content might be used at a later stage. So, while he isn't on-air, the operator should try to prevent making sudden moves etc. The ISO content is typically used for b-roll
B-roll
B-roll, B roll, or Broll is the supplemental or alternate footage intercut with the main shot in an interview or documentary.- History :The term B-roll originates from the method of 16 mm film production from an original camera negative...
shots such as people's reactions when it's uncertain if, when, and how they will react.
For television productions with more than one camera in a multiple-camera setup
Multiple-camera setup
The multiple-camera setup, multiple-camera mode of production, or multicam is a method of filmmaking and video production. Several cameras—either film or professional video cameras—are employed on the set and simultaneously record or broadcast a scene...
, the tally lights are generally illuminated automatically by a vision mixer
Vision mixer
A vision mixer is a device used to select between several different video sources and in some cases Compositing video sources together to create special effects...
trigger that is fed to a tally breakout board and then to a special video router
Video router
A Video router or Matrix are used for transporting video signals from sources or inputs to output destinations.- Inputs and outputs :...
designed for tally signals. The video switcher keeps track of which video sources are selected by the technical director
Technical director
The Technical Director or Technical Manager is usually a senior technical person within a software company, film studio, theatrical company or television studio...
and output to the main program bus. A switch automatically closes the appropriate electrical contacts to create a circuit, this lights the tallys located in the camera control unit
Camera control unit
- 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 to and from the camera, and can be used control various camera parameters such as iris...
s (CCU). If more than one camera is on-air simultaneously (as in the case of a dissolve
Dissolve (film)
In the post-production process of film editing and video editing, a dissolve is a gradual transition from one image to another. The terms fade-out and fade-in and are used to describe a transition to and from a blank image. This is in contrast to a cut where there is no such transition. A dissolve...
), during the duration of the transition the tally lights of both cameras will remain lit until transition completion.
With the increasing complexity of modern broadcast installations it is more common to find that a third party controller will manage the tally information along with mnemonic and crosspoint information from the video router
Video router
A Video router or Matrix are used for transporting video signals from sources or inputs to output destinations.- Inputs and outputs :...
e.g a "TallyMan" unit from UK based company TSL.