posted 09-06-2017 03:53 AM                    

quote: Leo Enticknap

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Interesting! I'd be very interested to know how their reliability and longevity compares to the longer established European and Japanese brands.

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I only know one small exhibitor that actually uses them and they seem to be content with them. According to them, they perform about as well as the Osram bulbs they replaced. You can't base any reliable statistics on a single venue though and they're just using 2K bulbs, it's the high power ones were it starts to get more interesting.

You have to ask yourself the question if you want to risk thousands worth of damage by saving a couple of hundreds. Although they offer warranty on both hours and projector damage resulting from premature failure, I know nobody who ever used it. Also, if you're on VPF, you really should check your contract before you start to put "non-certified" lamps into "your" equipment.

There was the occasional rumor, those PlusRite bulbs were just the repackaged bad apples from Ushio and/or Osram, but that's just rumour, they most definitly look different on the details. They also don't look shoddy, but you can't judge a book by it's cover alone obviously.

But they're there and I guess they will be around for quite some time. I guess they will have a pretty major foothold in their domestic market already. So, if the supply from the big brands would ever run dry, I'm pretty convinced there will be alternatives. Even though they might not be as good as an Ushio bulb, it still beats not having a bulb at all.

quote: Leo Enticknap

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I'd guess that coming up with the custom optics and/or mirrors is a more viable engineering challenge (given the size of the remaining, long term market for film projection) than an entirely new illumination source from scratch. It might even be possible to come up with a kit that could be retrofitted into existing lamphouses, like the kit that Barco sells for converting a series 2 projector from xenon to laser phosphor.

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Optics seem simple enough, until you actually start to dive into it. Then you quickly understand why it's a real science.

Back in about 2012/2013, when I was actively looking into it, as a kind of pet project, I had a chat with an optics specialist about it and it's pretty interesting what he had to say about it, because current RGB laser setups essentially use the same setup.

According to him, a setup with a parabola mirror wasn't feasible, because in order to cool and mount the LEDs, you need quite a lot of infrastructure behind the LEDs. If you don't actively cool them, they die almost instantaneously at the required wattage. So, bending the light around the assembly efficiently would be close to impossible.

Then, there might be the solution of stacking a lot of those arrays and use a whole bunch of lenses, mirrors and/or prisms to focus it on a single spot. Although this would be feasible, the optics system to achieve this would be huge and horrendously complex and expensive to built.

So, the other option would be to use "light pipes" or fibers. Every LED array itself would be a contained module, which focuses the light on a single fiber. Those fibers would then be bundled as closely as possible to a single spot. Then you only would need some kind of diffuser lens and some other simple lenses to focus it right onto the gate.

In such a setup, you would have the added benefits of a modular setup for your primary light source. Those LED arrays will eventually fail and you could replace them one-by-one. Also, like in some of those laser setups, you decouple the "lamp house" from the projector, which allows greater flexibility of placing the actual light source.

quote: Steve Guttag

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I think the big TV screen Samsung and Sony are developing is the bigger end to projectors (film or digital) than alternate light sources. I really think in less than 10-years time, they will be the norm for new installations.

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posted 09-06-2017 08:20 AM                       

quote: Scott Norwood

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Leo--that is interesting about the non-striking old xenons. I have personally worked in places with original bulbs that were 20+ years old and worked fine (obviously, these are performing-arts houses that occasionally show films). I can absolutely believe that the seals would fail over time, though.

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posted 09-06-2017 10:06 AM                    

quote: Leo Enticknap

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When I first worked in a movie theater (1989), the chief projectionist there would opine that xenon arc bulbs were probably invented by IRA terrorists as a dastardly means of killing us, because they exploded so often and with so little provocation.

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