I just came back from the Inspiration Conference, and there was much discussion about which console to use to control your lights. With the proliferation of moving lights that are available, and with the costs dropping, the question of how to communicate between the lights and the console is popping up more and more. In order to understand this issue, we need to understand the differences between a conventional system and a moving lights system.
In a conventional lighting system, the fixtures are connected to a dimmer rack directly; the dimmer rack is connected to the console by a digital control language called DMX512. The console talks and the dimmers listen. The only attribute of the fixtures that you can control remotely is the intensity; any other changes such as focus and color require going up to the fixture.
In a moving light system, you hang the fixtures in the same location as with a conventional system, but you don’t necessarily have to provide power through the dimmer rack. Also, data is sent from the console using a data cable which speaks the DMX512 language. You have control over all the attributes of the fixture, such as focus, color, patterns, sometimes even the ability to turn them on and off.
Going into further depth, let’s discuss what the DMX512 is. DMX512, “Digital Multiplex”, is the language that the console uses to communicate to the outside world; there are many devices manufactured that can listen to DMX512 other than dimmers or moving lights. DMX512 is a digital language with a defined set of parameters; the only one of interest to this article is the quantity of information that can be transmitted down a pair of wires. Each DMX512 cable can carry 512 separate values of information from the console to the devices; each value is referenced by its address in the data stream.
With the conventional system, each dimmer occupies 1 address of the 512; the standard full size dimmer rack holds 96 dimmers. A standard installation has 1 to 2 dimmer racks, so most places use less than 200 of these addresses.
The moving lights systems are different; the lighting fixtures come in a variety of configurations which utilize different amounts of addresses, anywhere from 8 to 60. The quantity of addresses required by a moving light is determined by how many attributes the fixture has, such as pan, tilt, color, gobo, etc. Each attribute requires 1 address and some attributes require 2 for finer control.
So, at this point you’re thinking, “I just add up the number of dimmers I have, and the number of addresses my moving lights require, and I will know how much my console system can handle.” However, there is a problem. Lighting consoles are defined by how many channels they control not how many DMX addresses they can talk to.
For example, ETC produces a line of consoles called the “Express” line. Within that line, consoles range from 96 to 250 channels per console, while each console has the ability to talk to 1024 addresses, or 2 “Universes” of DMX512.
Why is this of any importance? Well, for example, a High End “Technobeam” moving light fixture requires 18 channels. Each attribute’s address must be patched to an individual channel. If we had 10 moving lights, this requires 180 channels of our console. Now you can patch more than one address to a channel. This is useful with dimmers if you want to patch all 30 house light dimmers to one channel, for ease of control. This does not work well with moving lights because you want to be able to control each moving light independently, so you would patch each address to a channel.
As you start to add moving lights into your conventional lighting system, the number of control channels available becomes the determining factor in calculating how many fixtures you can add to your current console. When just starting out with a few fixtures, most theatrical style consoles will work just fine. If you are considering a larger quantity of fixtures, you begin to make the jump to a new or additional console. Now you run into the next problem, finding a console on the market that controls both conventional and moving lights equally well at the same time.
Programming for a large moving light system requires a different approach than programming for dimmers. On the large Broadway touring shows they will use 2 consoles if it’s a mixed system, one for the conventional system and another for the moving lights. Once the show is programmed, they slave the moving light console to the conventional for consistent playback.
You may choose to do the same; to add a small dedicated moving light console and keep your conventional console. That way, for standard services you may not need to have trained moving light operators, while you will have the flexibility to produce more complex effects for special events or shows. Consider also the amount of programming time required to produce good effects with moving lights. If a normal Christmas pageant requires 5 to 6 hours of conventional programming, then a complete moving light pageant could require 5 times that amount of time for programming. If you do choose to use moving lights in your standard services, you can come up with several “patterns” Once you have programmed your standard looks for normal services, they should be easy to control and make slight modifications, but remember to allow enough time for that initial programming.
So the answer to the question of when to buy a moving light console comes down to a few points:
• How many channels do you have now with your console?
• How many moving lights are you planning on?
• How many channels do they require?
• Are you looking to go with all moving lights or live in the mixed world?
If you have any questions or would like more clarification on your specific requirements, please send me an email, firstname.lastname@example.org. I am always looking for questions to include in this column, feel free to contact me.