Plasma Lighting: Another Tool for the LD Arsenal

In Uncategorizedby tfwm

Just when you thought you had your lighting budget all figured out, a new technology is on the scene. It is sleek, small, and energy efficient. It is referred to as Lifi® or plasma lighting. And it may be coming to a facility near you.

Another energy efficient technology is just what the lighting industry needs, right? The lighting industry is certainly one of the fastest moving, and lighting is arguably one of the more scrutinized technologies due to the fact that it has so many direct correlations with energy use. Energy efficiency and a smaller format “package” is appealing to people who are looking for new options. Plasma technology effectively has both of these things.

Lighting designers may not have had enough time to catch their breath after the last shift in lighting standards. Many houses of worship have recently augmented parts of their architectural and stage lighting with LED. The question is: does this mean that all these lighting products need to be swapped out again?

You may not have to worry about that happening with Plasma lighting. Plasma has inherent benefits, just as LED does and just as conventional fixtures do. In retrospect, LED did not take over conventional fixtures. It most likely won’t, either. There were advantages that conventional fixtures had over LED right from the start, such as color rendering or how well it renders colors under its light. (See our November 2007 cover story on LED for more information on this) The same applies for Plasma lighting; it has certain limitations and some very commendable advantages.

Plasma lighting is energy efficient; it converts electricity to RF (radio frequency) energy to excite the gas in the bulb and create a plasma ball, which gives off light. It is also exceptionally compact; current manifestations of Plasma bulbs are roughly the size of a Tic-Tac.

The light output from this teeny bulb is incredibly impressive. Tony Hansen, Lighting Designer/System Consultant for Techni-Lux in Orlando Florida, can attest to the splendid power of these bulbs. He was first introduced to the technology at the end of a seminar he was conducting at the LDI 2007 conference. As people filed out of the room, a mysterious gentleman approached him and held out his hand. In the man’s palm was a plasma bulb configuration, which the man proceeded to power with a 9-volt battery. It nearly lit up the whole room.

In comparison to a conventional bulb, LED emitters and plasma bulbs have a much higher lumen output per watt of electricity consumed. Plasma puts out a hefty 67 lumens per watt, compared to the output of 15 lumens per watt for the old traditional light bulbs, while LEDs output anywhere from about 60 LPW up to 100 LPW in white light. But the small bulb size of the plasma lamp makes the collection efficiency very high, thus increasing the efficiency of any fixture in which it is used.

But efficiency without quality of light is not going to help most churches. However, this lamp has certain advantages that give it an edge.

“Because there is no filament or electrodes, the light it produces is extremely uniform,” said Richard Cadena, author and Editor of Projection, Lights and Staging News magazine (PLSN). “When you look at the beam you see no hot spot or aberrations at all. It’s amazing.”

Plasma, even as a somewhat new technology, is already being used by products in the theatrical lighting market today- including the Robe Robin 300 Plasma Spot and the Ocean Optics SeaChanger Nemo.

Currently, the largest plasma lamp is a 266 watt package, but the manufacturer has plans to soon release a 300-watt version and sometime in the future a 400-watt plasma lamp will be manufactured. The Plasma bulb configuration is developed and patented by Luxim Corporation out of California.

Plasma lighting, given its formidable light output, is able to fill in a hole that has existed in the area of energy efficient follow spots. LED has not been able to reach this benchmark, although companies are still hard at work to find a solution for this.

Still, this does not put Plasma on a pedestal over LED or conventional halogen fixtures. It instead starts to look more like a linear comparison. You have strengths and weaknesses for each technology, and each type does its part to fill gaps in requirements for theatrical and architectural lighting.

As Cadena explains, “Plasma lighting is not going to replace LED, or for that matter any other conventional lighting technology. Seldom does one technology totally displace another; rather, we typically augment our lighting toolbox with new technology and use them for different purposes. It would serve the house of worship well to consider the benefits of each of these technologies and how they best fit the needs of the facility.”

Even though each technology could have a potential place in a theatrical lighting configuration, there are some things to watch out for, specifically, color temperature and color rendering. Each lighting technology handles and represents light differently. Having conventional fixtures, LED as well as Plasma lights all on the same platform could cause big problems, perhaps not for the naked eye, but certainly for video applications.

“One of the things people forget when blending technologies, is that you are blending color temperatures,” explains Tony Hansen. “The problem with light, whether you take Plasma source or arc source or conventional source or LED source, is that you are resetting white every single time. The video camera creates a mish-mash of white reference, or white balance. You no longer have a white balance because there are all these different whites. The question becomes: what is the reference white for the system: which one becomes the dominant?” This “mish-mash” of white reference only becomes all the more noticeable as high definition cameras and displays are implemented.

Of course, this problem existed prior to Plasma lighting coming onto the scene. With a new variable to potentially add into the mix, it is important to keep color temperature considerations in mind. That is not to say that there aren’t ways to incorporate each technology into a facility; it can be done, and done well, if the entire game plan is kept in mind.

In addition to the aesthetic qualities of plasma lamps, there are benefits on the practical side as well. Most conventional and automated lights have an average lamp life of under 1000 hours. Even with extended life lamps, the maintenance can be daunting, especially for houses of worship, many of whom rely on volunteers or part-time staff. The 10,000 average life of the plasma lamp means that a fixture might run for many years before it needs to be replaced. And changing a LiFi lamp is as easy as replacing an HPL in a Source Four fixture; you simply change the emitter, which is a package containing the bulb, a ceramic disk, and a heat sink. The replacement cost is about the same as that of an arc lamp such as an MSR or HMI.

When any new technology comes onto the scene, we would do well to pay attention to the inherent advantages and disadvantages of each. Plasma lighting is something to certainly keep an eye on for the future, especially as we see it implemented into more and more fixtures and facilities.

As we continue to understand this technology and as more products adopt it, we will be able to call attention to real world scenarios where all of these technologies are being used at once within a facility. An encouraging thing to take from the emergence of Plasma lighting is that it represents evidence of manufacturing companies continually developing energy conscious methods to tastefully light buildings, events and productions.

Kevin Rogers Cobus is Executive Editor of TFWM. He can be reached at krc@tfwm.com. Considerable thanks to Tony Hansen, Stephen Ellison and Richard Cadena for their contributions to this article.