KnowHOW: Incorporating moving lights
KnowHOW: Incorporating moving lights
If you are looking to incorporate moving lights into your lighting rig, it may be a bit overwhelming to know where to begin. John Black discusses what to consider to get started
It isn’t often you attend an event where moving lights are not a part of the lighting rig and many mid- to large-sized worship venues also incorporate these fixtures. When the moving light market was in its infancy, these fixtures were accessible only to those with deep pockets and where their size and noise weren’t a factor. Now, the market is saturated with options to meet large- and small-scale events, budgets big and small, and abounding in features for lighting designers to take advantage of whatever the project needs are.
In this article, I’m going to discuss considerations before incorporating moving lights, how to select a fixture, and what you need to be aware of after you incorporate these fixtures into your rig.
First things first
Moving lights, aside from the cool-factor of the effects that can be created, provide a lot of flexibility. Within a single event, the fixtures can be focused on an infinite number of locations on stage, be recoloured as needed, project a number of different patterns and more. What would otherwise involve large quantities of conventional fixtures for a particular design may be possible with a smaller quantity of moving light fixtures that can meet a variety of needs. Their flexibility is one of their greatest strengths. Before incorporating them into your rig, however, there are several important factors to consider.
The two main technical considerations are power and control. First, let’s consider power. Unlike conventional fixtures powered through a dimming circuit, automated fixtures – whether LED or tungsten sourced – need a constant power source. This is because of the chipsets that process the control signals and control the various parts of the fixture.Therefore, you need to consider how it is that you will power your moving lights. When I began adding moving lights and LEDs into my rig, I had a simple solution to this. All of my venues had extensive power distribution systems installed running to a machine room with dimmer racks made by ETC. All I needed to do was replace the rack modules for the locations I wanted to plug in my moving lights with modules that were non-dimmable and allowed a constant electrical current to pass through the system. This meant no new infrastructure was needed and, when wanting to reposition fixtures for different events, I could simply move the non-dimming modules throughout the racks according to the specific circuits I wanted to use. This also meant I didn’t need to run temporary power extensions to the fixtures.
The second consideration is control. Conventional fixtures have a single control parameter – intensity. The lamp is either off, full on, or dimmed somewhere in-between. Control data is actually routed to the dimmer racks with only a power line running to the fixtures. This is not the case with moving lights. In addition to power for the fixture, moving lights require a direct data line to control all of thefixture’s controllable parameters. Prior to purchasing moving lights, make sure that your control console has the capabilities to control the fixtures you are looking at and that you can run or connect data cabling to where you want to place the fixtures. Control data can be daisy-chained from fixture to fixture, so having data distributed to each lighting position is a great way to ensure you have built-in flexibility. In addition to the physical infrastructure of data, be sure to consider the capabilities of your control console – will it support the quantity of control channels needed for moving lights? How user-friendly is it to program moving lights (especially if your technical staff is made up of volunteers)?
There are many more things to consider, but these are, in my opinion, the two most important considerations. I discuss in more detail the power and data needs for moving lights in the January-February 2016 issue of Worship AVL.
Know what you’re looking for
The next step is to sort through all of the available options in the market. There are three main considerations that I keep at the forefront of my decision process: fixture class, features, and serviceability.
When I think about fixture class, I am really considering the brightness of the fixture, or the amount of light that it puts out. I don’t want a fixture that will be underpowered compared with the rest of my lighting rig because I won’t be able to achieve the lighting looks desired. I also don’t want a fixture that is overpowered because there are negatives to running the fixture at less than its intended output simply to balance the output with the rest of the rig. This can especially be a problem with any video work being done. I first consider the venue that the fixture will be used in, particularly the throw distance(s) that the fixture may be used for as well as the lamps used in the rest of the rig and light-level that the stage is typically lit at. This helps me consider if I should be looking at a 700W or a 1,200W source fixture as an example. The brighter the light source, the more power the fixture will also draw, which causes me to consider the power capabilities of my system. Also, the brighter the fixture, typically the larger the unit will be, which causes me to consider where the unit will fit into the rig. All of these factors are how I would define fixture class.
Fixture features refers to the specific ways in which the fixture can manipulate or produce the light beam. The simplest feature to decide on at first is whether you want an LED source or tungsten. LED moving lights are newer and have quickly gained momentum in increasing their brightness to compete with tungsten options. The next feature decision pertains to the shape of the beam that is produced. Most moving lights are generally categorised as profile/spot, wash or beam fixtures. Profile/spot units produce a focus-able beam that excels in the projection of gobos, aerial effects, and now often feature framing shutters. Wash units produce a wide, soft beam that excels at projecting large pools of light. Beam fixtures project very narrow and focused shafts of light often used for aerial effects. A more recent consideration is whether you need framing shutters or if an iris will suffice. What colour mixing system do you prefer – CMY mixing, colour wheel, or a multi-colour LED source for additive mixing? Do you need colour correction filtering to adjust the colourtemperature, or on the LED side of the market, what colour temperature lamp source do you prefer? If you aren’t sure of what features are important to you and your workflow, I suggest you set up some demo sessions with some local suppliers, or even look at renting some fixtures to test out before making a purchase.
Answers to the first two questions will really help narrow down the fixtures on the market to a handful of options. The third question that always plays an important role in my decision-making process is serviceability. Moving lights have lots of, well, moving parts. They require more servicing than conventional fixtures. Is that servicing something that you and/or others on your technical staff are qualified to undertake, or will you be needing a service contract with a local distributor to help you ensure that the fixtures are operating as they should be? If something happens to a fixture, how quickly can you get replacement parts or the unit repaired so that there is minimal downtime? Moving lights are a significant investment and so careful consideration should be made regarding the upkeep of those investments to maximise their useful life.
We’ve got them…now what?
Perhaps the most obvious direction to take this last section is how to use the fixtures. The challenge lies in the fact that answering ‘how moving light fixtures are incorporated’ has as many answers as there are stars in the sky. Each situation is unique as the combination of fixtures used, the lighting positions they are hung in, the venue you are operating in, the style of your services and events, and more are all as unique as each person reading this article. And in that lies the beauty of working with these fixtures – the design possibilities are endless.
Instead, I want to focus on the responsibilities that come with having these tools at your disposal. After all, they aren’t going to take care of themselves and keep running forever. Moving lights are sensitive instruments often put under a lot of stress. It takes frequent, diligent preventative maintenance to ensure that your return on your investment is maximised, especially in a house of worship setting where budgets are often tight and technical systems are run by volunteers. Here is a quicklist of easy preventative tips to keep your fixtures running:
- Ensure that fixtures are powered correctly. If moving light fixtures are powered mistakenly through a dimming circuit, the processing boards can be damaged.
- Ensure that the fixtures are powered down correctly. Especially with tungsten-source fixtures, be sure to turn off the lamp and allow the fixture to stay powered ‘on’ (meaning fans running) to bring the internal temperature of the fixture down. It will prolong the life of your lamp and internal components that are subject to the build-up of heat.
- Regularly open the fixture and blow out any dust that has built up on the fans or other components.
- Regularly clean the lens(es) and lamp with alcohol pads (never touch these with your fingers as oil from your skin will be transferred).
- Power off the fixtures when not in use. Even if the lamp is ‘off’, if the fixture is powered on the processing boards will be running.
There is more to the maintenance of moving light fixtures, but following these five basic preventative steps will help you maximise the lifespan of your fixtures.
I hope that this has provided some tips if you are considering or already incorporating moving lights into your lighting rig. They are workhorses in my venues, and I hope that you can experience the increased flexibility and design possibilities in your own work.
John Black serves as the theatre manager for Seoul Foreign School in South Korea. He especially enjoys sharing his passion for entertainment technology with high-school students each year through his student production team, Crusader Live!