Lighting Focus: New Lighting Technologies
LIFI plasma lamps and LEDs are changing the landscape of theatrical and broadcast
I initially saw the LIFI Solid-State Plasma lamp from Luxim Corp at Lightfair in 2008 when Luxim was showing it for projector applications. The product is now crossing over to the entertainment market through some alliances with entertainment lighting manufacturers.
Many people encountered the LIFI when SeaChanger launched its Nemo color-changing ellipsoidal with the LIFI plasma lamp at last year’s LDI tradeshow. Recently, the automated lighting manufacturer Robe introduced the Robin 300 Plasma Spot, a moving head spot luminaire that uses the LIFI technology. These are just the tip of the iceberg and I think that you will be seeing a lot more products using this pretty remarkable light engine. You will definitely be hearing a lot more about this lamp in the weeks and months to come if you haven’t already.
LIFI is a solid-state light source that is not a light emitting diode (LED) and has no electrodes like a metal halide or discharge lamp. It is a high-intensity light source that brings energy efficiency, long useful life, full spectrum light and is dimmable from 20 to 100%.
This tiny light source—the lamp itself is about the size of a Tic Tac—has a nominal power draw of 266W, yet outputs up to 17,800 lumens with a color-rendering index (CRI) of 94 (out of 100) and a rated average life of 10,000 hours. The lumen output will be reduced once the lamp is inside the lighting fixture; typically the final lumen output is at 10,000 lumens.
“The LIFI-ENT-31-02 allows fixture manufacturers to replace short- and medium-arc-length HID lamps in 400 to 575W categories,” explains Apurba Pradhan, senior technical marketing engineer with Luxim. “In this wattage category, we are engaged with several manufacturers that typically use HTI or MSD lamps.” Since heat is directly related to the wattage, the LIFI plasma lamp produces about the same heat per watt as standard discharge lamps, however since it is using less wattage per lumen it does run cooler to achieve the same lumen output. There are fins on the emitter housing to help shed the heat away from the electronics.”
When you look at the efficacy of a fixture, you want to see what the Lumens per Watt (LPW) are for the fixture and lamp as a whole system. To get LPW, you take the System Lumen Output and divide it by the Input Wattage. Most discharge lamps that are currently used in automated lights have an overall efficacy of 15 to 30 LPW. The LIFI plasma source raises this important number to 30 to 45 LPW. You get similar light output with less wattage drawn. “Let’s take the 400W medium arc HID lamp which runs at 440W due to ballast inefficiency for example,” says Pradhan. “The LIFI-ENT-31-02 outputs equal fixture lumens but at 290W.”
Ten thousand hours lamp life is a big improvement over the currently typical 750 to 1,000 hours. To put 10,000 hours in perspective, if you used the light for four hours a day, seven days a week for 52 weeks, the LIFI lamp would last close to seven years. When you do need a replacement lamp the cost would be approximately $150. This would be to replace the emitter consisting of the bulb, puck and heat sink. The emitter rated life is 10,000 hours; however the driver is rated for 60,000 hours. Therefore, in most cases you would never need to replace the driver.
Real World Applications
The good news is that there is a cool, cutting-edge light source out there; the great news is that there are already two manufacturers that have integrated the LIFI source into their products.
SeaChanger Nemo
SeaChanger, best known for its CYMG color changer for ETC Source Four Ellipsoidals, produces the Nemo, a color-changing ellipsoidal that uses the LIFI solid-state plasma source. The Nemo produces 10,000 lumens with a draw of 300W, which means that it outputs 33 LPW. It comes equipped with SeaChanger's own Extreme Green wheel that extends the CMY color gamut to create more dramatic, vibrant colors. The SeaChanger Nemo uses an existing ETC Source Four front-end barrel as well as an assortment of ETC lens tubes.
Because of its lamp life, Nemo is the perfect solution for hard-to-reach installations like domes, atria and high ceilings. “It bridges the gap between incandescent and LED lighting at a price that's within reach,” says Beth Weinstein, marketing director for SeaChanger. The first Nemo prototype was shown at LDI 2008 in Las Vegas; the final product was shown at Lightfair 2009, where it was awarded the LFI Innovation Award in the Specialty Lamps category. It is currently being specified and the production units are scheduled to ship early this summer. SeaChanger has development plans for the Nemo—on deck now are the standard fixture, which can be used in theatrical and architectural installations, and an outdoor fixture that will have all of the same functionality, but with a housing that can withstand hard rain.
“The response to the Nemo fixture has been overwhelmingly positive,” says Weinstein. “We have a ‘green’ alternative to incandescent lighting that can provide the seamless, silent, swipe-free color transition that people have come to expect from SeaChanger.” The list price for the Nemo is $3,800.
Robe Robin 300 Plasma Spot
Robe’s Robin 300 Spot uses the LIFI solid-state plasma light source and combines it with the company’s moving light technology to offer an optical system with a beam angle of 10° to 40° and a pan of 540° and a tilt of 280°. The Robin 300 has an output of 10,000 lumens with a 266W power supply for 37.5 LPW.
“We have designed a new color-mixing system that, combined with the plasma lamp technology, delivers outstanding color-rendering and superior color-mixing features,” says David Srba, CEO of Robe Lighting Inc. “I would say the colors are really the strongest feature of our new Robin 300 Plasma Spot. With the extremely flat and even beam, we see this product to be ideal for applications in theatres and houses of worship amongst others. If we add the life span and stability of the plasma lamp to the reliability of our products, Robin 300 delivers a great value product that will require very little maintenance and last for a very long time.” Another feature to note is that the LIFI lamp has a semi-hot restrike function—less than 120 seconds for full lamp brightness after shutting it off.
The Robin 3 series, which offers the LIFI lamp or a version of the unit with the Philips MSD Gold 300/2 MiniFastFit lamp, was introduced in April at the Prolight+Sound show in Frankfurt and the products went into production this June. “The response was extremely pleasant,” says Srba. “People are excited about the new technology.” Robe plans more products with the LIFI plasma lamp. At press time, the estimated US list price for the Robin 300 plasma spot is $9,500.
How it works
So now you know the LIFI exists and even where you can use it, but if you want to really get into how this new technology works read on. The official product name is LIFI Entertainment 31-02. The system consists of four primary sub-assemblies—bulb; radio frequency (RF) power amplifier circuit (PA); printed circuit board (PCB); and an enclosure. The PCB controls the electrical inputs and outputs of the lamp and houses the microcontroller used to manage different lamp functions. An RF signal is generated by the solid-state PA and is guided into an electric field about the bulb. The high concentration of energy in the electric field vaporizes the contents of the bulb to a plasma state at the bulb’s center; this controlled plasma generates an intense source of light. All of these subassemblies are contained in an aluminum enclosure.
The core of the LIFI system is the bulb sub-assembly, where a sealed bulb is embedded in a dielectric material. This design is more reliable than conventional light sources that insert degradable electrodes into the bulb. No electrodes also mean a cleaner beam and optics. The dielectric material serves two purposes; it’s a waveguide for the RF energy transmitted by the PA and it acts as an electric field concentrator to focus energy in the bulb. The energy from the electric field rapidly heats the material in
the bulb to a plasma state that emits light of high intensity and full spectrum.
The ENT-31-02 is the first of a series of products they are going to introduce into the entertainment technology market; Luxim is looking to broaden its products in this market. The company is in talks with manufacturers of film and studio lighting for daylight (5,600K) fixture options where the HMI lamp is dominant. The next product will be targeted at replacing the 700W HID lamp and then the company will target the 1,200W category.
“As the lighting industry is looking to save energy and reduce costs, LIFI is the most compelling solution for the next generation of spot, beam, and directed light applications,” concludes Pradhan. “We are excited for the future of the industry and hope to be the standard for long life, energy-efficient and true color light sources.” It may be cliché but the future really does look bright for this new technology.
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Side Bar:
LED’s and Their Applications in Churches
Don’t simply rely on product specifications. The key to whether or not the will they work in your situation depends on much more.
By Jerry Colmenero
LEDs as an emerging illumination technology has quickly taken its place among the viable choices for illumination. LEDs, incandescent lamps and discharge lamps are all used in lighting but these different methods yield different results, knowing where to use and how to apply these lighting methods is key. I have been approached many times with the concept of going “all LED” for church lighting applications. We are just not there yet.
Since the white light from mixing multicolor LEDs is a perceived white generated by specific frequencies of color as opposed to a broad spectrum light such as an incandescent lamp we have no single source generating the white light. Now this works well as long as there is a neutral surface reflecting the LED color spectrum back to the viewer. Objects that appear white reflect back nearly 100% of all the frequencies bombarding it, on the other hand objects that appear black reflect back very little.
Besides a Color Temperature measurement light sources also have a Color Rendering Index measurement or CRI. The Color Temperature of the light source does not indicate how well it will offer a viewer a balanced reflection of colors of a particular range. CRI is testing using a pallet of colors and their reflectivity against a reference with a given light source.
An “ideal” CRI is considered 100 (on a scale of 1 - 100) referenced against a daylight source. The CRI will not measure the same when comparing a discharge lamp source versus LEDs because the reference color temperature is different or non-existent. In other words, the CRI measurement from a halogen lamp and the CRI from a discharge lamp may be the same stated number but subjectively different. This means that the CRI from some lamp sources, especially LEDs, my have a high CRI number but the actual color rendering can be very poor.
My best suggestion is to sample your lighting inventory of conventional, intelligent, and LED fixtures and set up your own shootout and shine the lights on what you want to illuminate and subjectively view it and also view the image on video if your facility uses video. This can be a very revealing application test and and can lead you to make self-informed decisions on the application of your different light sources. A light source should never be chosen on the printed specifications alone, only a live test shows the qualitative differences and leads to the best results.
Michael S. Eddy writes about design and technology. He can be reached at mseddy2900@hotmail.com. Email Michael S.
