Nexera is an incandescent fixture with built-in patent pending dichroic CMY color mixing using three colored glass flags that can each be separately controlled up and down to combine any color in the spectrum. Each flag is controlled through a designated DMX channel, receiving and sending signals through the RAM power supply and a DMX console. To wit:
DMX Channel 1 controls Cyan (0%=no color to 100%=full saturation)
DMX Channel 2 controls Magenta (0%=no color to 100%=full saturation)
DMX Channel 3 controls Yellow (0%=no color to 100%=full saturation)
It is convection cooled, so there is no noisy fan, resulting in virtually silent operation. Plus, color changes can be made in real time. The four Nexera models consist of a profile with a tungsten source, a wash with a tungsten source, a profile with a CDM source, and a wash with a CDM source. The CDM models have an Aromat ballast attached to the underside. After undergoing testing, Aromat approved a five-year warranty on their ballast when used with the Nexera CDM models.
Wybron is not new to creating color. But early in the new millennium, after 25 years in the color changer market, Keny Whitright and his team felt it was time for the company to seek a new direction, applying its accrued engineering expertise to a new technology. And since dichroics were becoming more commonplace in theatrical applications, it seemed the natural direction; the Wybron team felt that theatre was ready for dichroic CMY color-changing fixtures. With the help of consultant and industry veteran Robert Mokry, the Nexera color-changing technology was conceived.
Wybron engineers quickly set to work on an aggressive product development schedule: designing, testing, and producing units in less than 10 months. By LDI of 2003, Nexera was born. Evolution of the Nexera created a technology unique enough to allow for a patent application.
It wasn't just the mechanical design that presented a challenge. The known consistency issues with most dichroics, combined with improving color integration (mixing) over what was on the market, added to the engineering requirements. One of the greatest challenges was to make all the fixtures match color at the same DMX values — which was eventually achieved. This required the purchase of nearly $50,000 of colorimetry equipment to test filters, reflectors, and assembled units. This also added a software requirement to the project so the testing could be automated.
“The original prototype for the fixture was made out of a single piece of 8-inch diameter steel pipe,” recalls engineer Scott Longberry. “Slots were milled in it by hand to allow the color changer to mount to it. Now we have extruded aluminum housings that are milled by state-of-the-art machines.”
Another big challenge was doing away with forced cooling. In order to solve this problem, mechanical designer Russ Warnecke says the company purchased a rather expensive piece of thermal analysis software, which proved helpful up to a point. “But in the end we had to resort to spending hours and hours experimenting with vent hole locations to achieve the results we were looking for,” he notes.
During the testing phase of the first batch of Nexeras, Warnecke and the R&D team noticed that after a few hours of operation the optical components would become hazy with some sort of film. “We initially thought that this was caused by a silicone adhesive out-gassing before it was completely cured,” he explains. “We replaced the adhesive, but the problem still existed. We then proceeded to replace several other materials that we thought might be the culprit, but nothing seemed to help. Eventually we concluded that it was the powder coated finish that was out-gassing. The coating never burned or showed any visible signs of degradation, but during the first few hours when it was at temperature it would out-gas enough to completely fog up some of the optical components. We then began working with our powder-coating supplier to find a solution. What we ended up going with is a silicone-based powder, which was initially formulated for the outdoor grill manufacturers. The performance of this coating was impressive enough that we have since begun coating all of our products with it. It can withstand extreme temperatures, it is very durable, and stands up extremely well against the elements.”
Currently in production are the Nexera DMX models. While retaining the original dichroic color-changing characteristics of the Nexera, the Nexera DMX has two new features. First, the Nexera DMX requires no external power supply, as the DMX signal compatibility is built directly into the fixture. All that is required is an 115/230VAC outlet and a DMX console, which translates to easy transport. These too will be available in profile tungsten, wash tungsten, profile CDM, and wash CDM models.
The second development of the Nexera DMX models is the built-in dimming capabilities in the tungsten models, achieved through a fourth DMX channel. In the tungsten models, it controls the percentage output of the light source, much like a dimmer in your home.
In the CDM units, the fourth DMX channel will operate a fourth flag with a reflective coating. This allows the user to pass through only as much or as little light as is desired.
Lighting designer Russell Champa got the chance to use the Nexera Wash units for the first time on a production of The Story at the Philadelphi Theatre Company. In this production, set designer Neil Patel had designed a series of 16' rolling towers backed with a material called Syn Skin. Champa used six of the wash units on the towers to provide color. “They worked well for this application,” Champa says. “The color moves and the color mixing were very smooth and very even. It has a tungsten source, so it balances really nicely with other [ETC] Source Fours. The field was incredibly smooth; we were able to get very deep colors with the tracking towers, and they were very bright.”
The designer discovered one interesting component of the Nexera units after the fact. “We needed to use a little bit of frost to spread the beam out,” he explains, “but found out later that you can actually take your Source Four PAR lens kit and drop different lenses from a Source Four PAR in front of the beam to essentially give you a wide or medium arc, which is a crafty little trick, I think.”
Champa notes that the wash units weren't without their drawbacks. “We did have one unit that didn't quite match so we had to tweak levels with it a little bit, and I'm not sure if it was a lamp-tuning issue or if it was due to flags made by different manufacturers; I never took the unit apart to see what was going on,” he explains. “The other aspect that was a little bit of a surprise to me was that you can't actually bump your color flags; the quickest they move is about one to two seconds. So you can't do a quick color changes, but that's easy to work around and in that instance we didn't really need it.
“Overall,” he concludes, “the Nexeras worked great for this application.”
Clifford Greer, the lighting supervisor at the Philadelphia Theatre Company, was also impressed. “As far as the way the color is introduced into the beam, it's better than what I've seen,” he says. “The changing is extremely smooth. They've got it down to allowing the designers to create color more often used in legit theatre, and didn't stick to a rock and roll fixture, which is cool.”