Marcus Marchesseault
March 21st, 2008, 05:03 AM
http://news.zdnet.com/2422-13568_22-192842.html
View Full Version : new light source Marcus Marchesseault March 21st, 2008, 05:03 AM http://news.zdnet.com/2422-13568_22-192842.html Allan Black March 21st, 2008, 05:21 AM Is it too late to buy shares in that outfit :) John Jay March 21st, 2008, 01:13 PM I was just about to post this then I saw this thread. Looks a great solution for daytime lighting Samuel Hinterlang March 22nd, 2008, 05:18 AM Good stuff Bill Pryor March 22nd, 2008, 09:19 AM Looks like double the output of equivalent LED. It'll be interesting to see how long it takes for something like this to get seriously on the market. It seems people were talking about the possibility of professional LEDs 6 or 7 years ago, and I just bought my first set recently. Richard Andrewski March 22nd, 2008, 07:03 PM Thanks for posting that Marcus. 140 lumens per watt. That's where it really starts to get more interesting than metal halide which is about the best hardlight source we have now. So, that means its putting out about 35,000 lumens or equivalent of about a 1750w tungsten unit of some kind. Thats great stuff--much better than the 85 LPW we get from metal halide. They key in all this is the cost as to whether it becomes mainstream. Sometimes it can take a very long time between initial announcement and when something actually becomes marketable. Then after that its a question of how quickly the early adopters help the price go down. On street lights (which is what these are primarily used for) its simply a matter of seeing how long the investment takes to pay back. Also, we don't know the CRI of this light although they say that the plasma process yields something like full spectrum daylight which sounds like really good news. Wonder what the UV output will be too... On stage / studio lighting the thought process about investment is not taken into consideration so much as a rough comparison in the mind of the buyer as to how expensive the fixture is next to the ones they are familiar with. If this is way over the top expensive, no one would buy it except for the fanatic early adopters. The price per lumen curve on LEDs is starting to come down to interesting levels. We've had a 60w single high power LED for about a year that I experimented with but found it too expensive to use in a fixture. After all, no one is going to buy a $1000 pepper fresnel. We also hated the color temperature and CRI of the unit and found the light to be a bit greenish. We have access to 100w LEDs this year and the price range of the pepper fresnel (about equivalent to 200w tungsten fresnel) would be more in the $600 range--better but still very high. Its not clear the CRI as they don't announce that. You have to remember that these people are designing these for the street light market which is far larger than anything related to film lighting and many make them to emulate a mercury vapor lamp which is about as unusable for our purpose from color temperature and CRI standpoint as anything could be. One problem with these types of lights is their need for a huge heat sink to keep them alive for their rated life time. That heat sink really presents a problem in incorporating the high wattage LEDs into a usable fixture (with focusing and glass fresnel or spot lens and of course a positioning yoke). This heat sink and LED combination also presents a bit of a problem in making a reflector that will work well with the LED too. I really hated the reflector that came with our 60w LED and it had a terrible bright spot in the middle of the beam which would have been hard to smooth out. So, all these are not impossible problems to overcome but certainly slow down the process and make it more expensive for tooling and design. On this particular "plasma" light in question, we don't know the particulars of heat sinking necessary, how it can work with a reflector, CRI, color temperature (and whether they can make it in other color temps) pricing, etc. but I'm sure we'll be hearing more as this does seem to be a totally different paradigm. George Kroonder March 23rd, 2008, 07:29 AM This isn't just a lab experiment, it is in production. FI Panasonic uses LIFI in their latest line of RP TV's. George/ Jacques Mersereau March 26th, 2008, 01:40 PM Projectors would be another great use. I wonder about heat, but with that kind of output I would guess that most of the energy must be turned into photons. Here is another site with more info: http://www.audioholics.com/education/display-formats-technology/lifi-lamp-technology-primer Richard Andrewski March 26th, 2008, 08:42 PM Yes I saw that link too. Some things don't add up about all this. In that link they say 4000 lumens and 270w draw. Thats about 14 lumens per watt! How is that better than tungsten or metal halide? And why is the other model used in the street light more efficient with 140 LPW? Except for the 20,000 hour stated lifetime, I don't see many other benefits to it in the projector area if thats true about the 270w draw with 4000 lumen output. Marcus Marchesseault March 27th, 2008, 04:04 AM Oops, I made a follow-up post before reading the article. The numbers in the article don't come close to the numbers in the video. In video I linked, their 250w light was much brighter than a 400W streetlight (metal halide?). I wonder what happened to make the projection set so inefficient. Richard Andrewski March 27th, 2008, 08:40 PM I sent in an inquiry to this company a few days ago and haven't heard back as I have a number of questions (Marcus' question about inconsistencies being one of them). I am always interested in new technologies like this and if theres a way to do it cost effectively and if it really lives up to the promises shown, we'll be all over it soon. Dan Wells April 2nd, 2008, 09:28 PM The CRI question has already come up... My other question would be reliability. I've had very varied luck with compact fluorescents in household applications (I have a five year old bulb that's still going strong, but I've also blown them in three months). I'm actually thinking of replacing a bunch of household bulbs with LEDs, because they are both almost as energy efficient as compact fluorescents and also almost indestructible. If these bulbs were both more efficient and also durable, that would be wonderful... -dan |