The Lighting System

A Day in the Life: Electrician

Check out this video from Playbill featuring the lighting crew from the 2011 Broadway production of Billy Elliot: The Musical.

Broadway 101: How a Broadway Show "Lights the Lights" Links to an external site.

(Length 6:27) from Playbill on YouTube

The basic lighting system

• Console: electrical board that allows for the manipulation and “cuing” of lights and effects
  • • can be either computerized or manual, although the majority of them are computerized
• Data: transmits information from the console to each piece of gear to tell it what to do
  • • transmitted through a system we call DMX-512
• Dimmers: increase or decrease the voltage going to a light to change its intensity
  • • most theatrical dimmers can handle a max load of either 1200W (1.2kW) or 2400W (2.4kW)
• Constant Power: circuit that supplies constant, consistent voltage
• Fixtures / Instruments: the lights and effects machines (hazers, foggers, and strobes) that are a part of the lighting system

What is DMX?

Short for "Digital Multiplex," DMX is the standard control language used for the lighting console to control the lighting equipment.

A single DMX cable can send 512 signals at once, which is known as a universe of DMX. Each one of these 512 signals is known as an address and sends a value between 0-256. Each lighting device on the network will listen to its assigned address for instructions and will do whatever the DMX signal tells them to do. In the case of a dimmer connected to an incandescent light, it will go to an intensity of 0-100%. For a moving light it might be to pan a certain number of degrees to the left.

Lighting systems with many moving lights and/or LEDs can have several universes of DMX operating at the same time. And a single light like a moving light or an LED can require multiple addresses in order to fully function and for the console to control all of its parameters (like pan, tilt, color, intensity, etc.).