Recently, I commissioned a renovation project for Northern High School in Durham, N.C. The district had chosen to accept the option to use LED fixtures for their cyc lighting. While the specification only required an RGB fixture, the system integrator provided the new Altman Spectra Cyc 100. When I went to commission the system and turned them on for the first time, I was impressed with the coverage and depth of color. This intrigued me, and I wanted to give them a more thorough workout.
Since I work at a proscenium theatre, I wanted to see if this fixture could replace the conventional 3-cell Sky Cycs lighting a 20-foot tall by 40-foot wide cyc. The Northern High School cyc was only 16 feet high and 30 feet wide. So I arranged to get seven units to test under actual show conditions.
Shedding Watts
The test was to see if the LED fixtures would provide the same coverage and intensity, along with smooth dimming during a production of the show Rent.
I set up the testing at East Chapel Hill High School, where they have a 20-foot-by-40-foot muslin cyc and they use six 3-cell Sky Cyc fixtures with 1500-watt lamps. The fourth electric where the cyc lights hang is 42 inches from the cyc pipe. The school has a counterweight system so I was able to vary the height to achieve optimum coverage from the fixtures.
We installed them on six foot centers, as per the manufacturer's recommendations, to make use of the six-foot molded power cord that they were supplied with as well as the power pass thru connectors to daisy chain the power from one end of the pipe. There is an optional three-meter (3.28-foot) power cable available as well.
The first benefit for making the switch to LEDs is in power savings. The Sky Cycs used a total of 27,000 watts. The seven Spectra Cycs are listed as 100 watts maximum with all LEDs on, for a total of 700 watts. That's a 97 percent reduction in power! Using a standard Edison wall outlet with a 15-amp connector you would theoretically be able to power 18 fixtures.
Covering the Cyc
I found that by flying the pipe to 21 feet 6 inches, I achieved the best vertical coverage across the 20 feet of cyc. The vertical coverage was not 100 percent, but in a side-by-side comparison with a Sky Cyc it was equal or better.
At first glance, the fixture looks like other Altman cyc lighting fixtures. The LEDs are mounted at the corner of a "J" style reflector. To reduce pixelization, the LEDs are mounted behind a frosted blending lens that blends the colors even at close range.
There are two more benefits that the Spectra Cycs have over other LED striplight style fixtures.
Benefit number one is the asymmetrical reflector that improves vertical coverage. Other fixtures make use of lenticular lenses to spread the light, which also reduces the output. The reflector is similar to those developed for the Econo-Cyc.
The second benefit is the use of amber LEDs in addition to the red, green, and blue. The traditional RGB fixture does not create all colors well because of the narrow spectrum being produced by the primary color LEDs. By adding amber they can achieve a better white and create subtler colors.
Multiple Personalities
This fixture has eight different personality modes using four to 10 control channels. There are three parameters that make up the personality; resolution, master and smoothing. The difference between the personalities is broken down by how much control you want over the colors, and whether you want a master and/or smoothing.
The master allows you to have proportional control over a color that you have mixed so that when you dim the fixture, the color doesn't shift and stays the same hue. Smoothing helps to reduce the steppiness seen when dimming LEDs over a long crossfade. There is a choice between 8-bit and 16-bit control over the RGBA colors and the master.
The simplest personality assigns a channel to each of the four colors. The most complex uses 10 channels of DMX and assigns 16-bit resolution to each color and to the master with smoothing turned on.
Smoothing is a software option that is either on or off and works internally, so it does need a control channel.
Photo Finish
The first test was to take photos of a Sky Cyc and a Spectra Cyc showing the vertical coverage and depth of color. The Sky Cyc is brighter in red, but in the blue and green, they are closer in output. Both types of fixtures are using additive color mixing – as you begin to mix colors, the loss of transmission in the blue and green gels used in the Sky Cyc is evident. The LED fixture becomes brighter the more LEDs you add to the mix.
The Spectra Cyc had better coverage at the bottom of the cyc. The Sky Cyc has a much more noticeable hot spot than the Spectra Cyc while the Spectra Cyc has more consistent color across the whole field.
The real test of the fixtures came during the show, in which the cyc lighting figured prominently. The Spectra Cycs allowed for a wide range of color choices including a wonderful amber, typically not available when using a conventional 3-cell cyc. In 8-bit mode, the dimming curve has some minor steppiness at the lower end, but smoothed out nicely above 30 percent. The stepping is not an issue with 16-bit control of dimming.
Three Times the Payback
I found the fixtures to perform without a flaw thoroughout the run of the show and I would recommend them for anyone looking for a more energy efficient source. There are three benefits to making the change; the reduction in power due to the lower power draw of the fixture and the reduced heat produced and thus the savings in air conditioning; the advantage of never having to change the lamp, which is huge, especially if the fixtures are hard to reach; and never having to change the gels. In the theatre in which I work we typically have to change the gels in our Sky Cycs six times a year at a minimum.
After testing out these fixtures I can see that using LED fixtures in the theatre is now feasible. The day is not far off when there might not be any dimmers in the theatre, only fixtures that are controlled through a data network. So it's a good idea to learn how to set up data networks and run consoles that easily control multi-attribute fixtures.
What It Is: LED cyc light
Who It's For: Any production needing to uniformly wash a cyc or flat with color.
Pros: Low power consumption, good colors, nice uniformity, versatile control options, long lamp life, no gel replacement.
Cons: Slightly less coverage, higher up-front cost than incandescent cyc lights.
How Much: $2,150 MSRP, excluding yoke (the yoke is $50)
