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Dimming Lights: Concepts and Options

In this article, Duke DeJong shares dimming concepts and gives options for people looking for dimming capability in their lighting.

Last year I was visiting a small church on the east coast. While there, our conversation turned to their lighting for the video camera. It seems that in some places, their pastor would appear bright on the camera while in others he would appear dark. The lighting wasn’t even across the stage, and when I looked up at the lights it was easy to see why. The lighting positions they had didn’t allow their fixtures to be roughly the same distance away from the stage, so some were closer and some were farther. We discussed a simple solution: dimming the lights that were closer to the stage in order to match the ones that were further away. The problem? Every par can was controlled by an on/off switch on the back wall. We needed dimmers.

Lighting dimmers are a pretty simply concept. They are used to increase or decrease voltage to a dimmable lighting fixture in order to adjust its intensity. Typically used with halogen or specific kinds of fluorescent and LED fixtures, dimmers give us the flexibility to set the mood and/or focus attention by simply turning lights on, off, up, or down. Ideally DMX controlled, you would send your dimmer a DMX value (between 0 and 255) or a percentage from 0-100% and the dimmer will send the lighting fixture plugged into it that much power. As anyone who has house lights that only turn on or off can tell you, dimmers play a valuable though often under-the-radar role in great lighting. There are four main styles of dimmers you see used in the church today, three of which are DMX controllable. But we’ll get to those in just a moment.

Quick Power Lesson

Before we dig into the types of dimmers available, it’s important to have an idea of how much power these dimmers will need. While portable/distributed dimming generally will work with a 20-amp circuit, most dimming packs will need much more. Here’s how you can do the math. Very simply, 20-amp circuits equate to 2,400 watts of power. If you break it down, that means for every 600 watts you have, you need 5 amps. A 12-channel, 1,200 watt per channel dimmer will need 120 amps to power it all. All in all, once you get into larger dimming set ups, an electrician must be involved to ensure proper electrical distribution. Unless you are a licensed electrician, please do not take this role on yourselves.

Four Main Types of Dimmers

Dimming Switch

A dimmable switch is dimming at its simplest form. While not terribly user-friendly for theatrical uses, if you have a super small lighting rig (maybe 4-8 lights) and this is all you can afford, it sure beats an on/off switch. Unfortunately your lighting console can’t control these dimmers, so you have to dim lighting “manually”.

Portable/Distributed Dimmers

Portable dimmer packs most often come in 4-channel packs (though they can range from 1-6 channels), taking one 20-amp circuit and dividing it into 4 channels of 600 watt dimming. For smaller venues, venues where dedicated 20-amp circuits are readily available and for smaller portable setups, portable dimmers make a lot of sense. With other dimming solutions, you centrally locate dimmers somewhere and run the power to the fixture. With portable or distributed dimming, the power is already near the fixtures, so you just need something to control the power output. Portable dimmers are generally DMX addressable, so if you address your standard portable dimmer to 1, it will receive DMX and control intensities for channels 1-4.

Portable/Distributed dimming comes in a variety of shapes, sizes, and price points. A variety of manufacturers make 4-channel dimmer packs, such as Elation’s DP-DMX-20L, which you would generally hang from your lighting pipe amongst the fixtures it’s powering with a standard lighting clamp. A sleeker, more elegant solution and one of my favorites is the ETC Smartbar, giving you the same function in a bar-style solution that you can mount your lights to if you choose. Ultimately, there are various options available in different form factors (and at different price points), but they all essentially accomplish the same thing—regulating voltage to the fixtures at your control.

Dimmer Packs

When building a new or retrofitting an existing building, generally people prefer a cleaner look without portable/distributed dimmers hanging throughout the room. In this case, instead of distributing the power to where the lights and dimmers will hang, we bring all of the power into one central location where dimmers are installed, and then distribute the controlled power to their final destinations. The first option that allows us to do this is a simple dimmer pack—typically rack or wall mounted. The packs often come in 6- or 12-channel versions and can range all over the map on how much power they offer per channel. For example, the ETC Smartpack SL1210-W offers 12 channels of dimming per pack with 1,200 watts per channel. Other models might offer 6 channels of 2,400 watts per channel, and others up to 12 channels of 2,400 watts per channel. You would then build a rack of dimmer packs or install a wall-mount version to give you the number of dimmable channels you need, and then distribute the power from the packs to your final fixture destination.

Dimmer Racks

In larger installations needing anywhere from 48 channels and up, you will often get into much larger dimmer racks which offer much more distribution, power, and flexibility. Just like our other options above, they provide varying amounts of power distributed to lighting fixtures for dimmable operation (typically either 1,200 or 2,400 watts per channel). Unlike our other options, though, their dimmer modules—generally in pairs of channels—are swappable, giving some flexibility in what you can provide power wise. For instance, last year my church added LED fixtures to our upstage lighting pipes, and those LEDs had their own built in dimming so they simply needed constant power, not dimmable power. I was able to purchase some constant contact modules for my ETC dimming system, swap those out with the dimmable modules for those outlets, and as simple as that, those outlets are now always feeding hot power and can no longer be dimmed. You can also replace dimmer modules with relay modules, giving you the ability to turn things on and off without the danger of browning them out by feeding them a partial voltage. And when I need those outlets to be dimmable again, I will simply pull the constant contact modules out and put the dimmer modules back in.

If your church is one that still runs their lights with on and off switches, hopefully this walkthrough of dimmers has helped alleviate and fears or concerns you’ve had towards converting to dimmable power for your lighting. With conventional lighting, dimming is really a critical piece toward making your lighting work for you in creating the mood that you want, or bringing focus to want you want focus on.

Duke is passionate about equipping the next generation of ministry leaders, especially those serving churches with technology. He serves as Church Relations Director for CCI Solutions, a design build technology solutions provider. Follow Duke on Twitter: @dukedejong

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2 responses to “Dimming Lights: Concepts and Options”

  1. Brian Adams says:

    Duke – thanks for the useful intro to dimming. One thing worth noting in relation to your original problem, i.e. lighting for video. Dimming the lights may well give even coverage, but introduces a new problem – the colour temperature of the lamps will change as you dim them, so the “bright” lights will look white, while the “dim” lights will look yellow.
    A simple, and very effective way of avoiding this problem, is to use dimming method number 5 – neutral density filters! The very obvious limitation is that they are not variable, but if all you want to achieve is equal light levels from all of your lights, they are the perfect solution, and are a lot more reliable than the even the best electronic dimmers! :)

  2. Paton parrish says:

    I am minister music Levelland Texas I need to replace system need estimate

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