Making Strategic Channel Assignments (part 1)

One of the repercussions of the advances in lighting technology in the last quarter of the 20th century was the proliferation of the number of circuits and dimmers available to the lighting designer in most venues.  This, in turn leads to lighting designs featuring many fixtures, circuits, cues…many items of information that a designer must retain and be able to call up at a moment’s notice.  There are several forms of paperwork that the lighting designer traditionally uses to organize this information.  However, with careful planning, this information can be organized in a logical manner so that it is easier to remember and easier to call up during certain phases of the lighting design process when time is at a premium and delay might mean holding up progress of many collaborators and cost the production time and money.  I want to start by examining the organizational principles that logical channel assignment can provide.

By way of explaining this idea, let us examine a simple lighting challenge.  Below is the diagram of a stage divided into 9 lighting areas.

Simple stage divided into 9 lighting areas identified by letters A-I

For the moment, let’s ignore issues related to the size and placement of the lighting areas and take it as axiomatic that the stage might be divided thus by the designer for any number of reasons.

Let us also assume that the Lighting Designer desires to provide lighting at approximately a 45-degree angle from a front-of-house position.  Many theatres will provide one or more such positions (often called “Beam” positions) within the architecture of the theatre.

Lighting Areas shown on a small proscenium stage

 Notice that it is easy to identify which instrument is assigned to each area because of the corresponding letter at the front of each symbol indicating the “focus”.  Also note that the fixtures are numbered within the body of each symbol with an “instrument number”.  These numbers begin, according to tradition and graphic standards, with the lowest number  stage left (audience right) and are sequential with the highest number being on stage right (audience left).

 Each fixture needs to be connected to a circuit.  Assuming a rather generous provision of a permanent circuit provided every 18” along the lighting position (This is the industry standard for instrument placement to provide room to manipulate and focus each instrument) and dimmer-per-circuit, the fixtures might be circuited as shown below.

1st Beam SL area lights with circuit assignments (in circles)

Notice how inconvenient it would be to bring up a line of these lights across the front of the stage (areas A, B, C, & D).  If one were to have to address them by circuit/dimmer number one would need to key something like the following into the light board (these keystrokes are those required of the operator of an ETC Expression III):

[dim] [3] [6] [and] [3] [0] [and]  [2] [6] [and] [2] [0] [enter] [5] [0] [enter]

This represents 16 keystrokes in order to bring up these 4 fixtures to a level of 50%

1st Beam SL area lights with channel assignments (in hexagons)

In the diagram above channel numbers have been assigned to each instrument.  Recognize that those assignments are made respective to the lighting areas (rather than to the physical placement of the fixture or the potentially arbitrary circuit/dimmer assignment.)  Notice that those assignments are sequential with the area hierarchy.  Thus, channel 1 is assigned to area A, channel 2 to area B, channel 3 to area C…ending with channel 9 assigned to area I.

Notice how the strategic assignment of channel numbers (in hexagons above) permits the designer to save keystrokes while doing the same task as follows (again those for an ETC Expression III):

[chan] [0] [1] [through] [0] [4] [enter] [5] [0] [enter]

This represents 10 keystrokes to bring the same 4 fixtures to a level of 50 (over a 33% reduction in time).

Additional time will be saved as the designer and/or the board programmer will be able to call to mind the number needed to address each instrument much more quickly.

In the future, I hope to allow the reader to link to a larger version of the full drawing of this and other diagrams that might be useful to the reader in understanding the topics under consideration in this forum.

See Part 2 for further exploration of this topic


Have fun!  But be safe!



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