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Author Topic: Helios bulb comparison... recommendations? Jack Ondracek Film God Posts: 2348 From: Port Orchard, WA, USA Registered: Oct 2002 posted 02-10-2009 09:58 AM                        I try to keep an open mind about bulbs, with a couple of notable exceptions. In my place, Christie bulbs seem to outlast everything, followed by Superior Quartz (for 7kW), and after that, most everything else. I'm wondering if anyone has a current performance comparison of higher wattage Helios bulbs. Last time I saw much conversation about this, the general opinion was that they put out more light at the start, but dropped off quickly and were hard to get to warranty. That was over a year ago though. Still the same? Any better? Do I have to buy one and try it myself? I'm running Big Sky pedestal mounts here, running between 4,000 and 7,000 watts.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 02-10-2009 10:00 AM                     Jack, I'd be much more inclined to run the Christie CDXL's which are their Helios equivelent than to actually run the Helios... The Helios have a very bad track record for reliability. Either should work fine with your Big Sky Mirror but unless you want a dented mirror stick to Christie. Also, Christie produces Osram's larger sizes of Short Gap Lamps but that fact is kept very secret... by Osram! Mark  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 02-10-2009 12:58 PM                     I tried a LTI Helio's 2k and I just barely got my warranty hours out of it- got 2300 hrs and was beginning to flickering badly on the pull. ..whereas Christies, with the warranty hour at 2400, I can almost get double hours on one bulb. True, they have great light, but not the duration. Thus, which side of the fence do you want then: Great light, or duration. When an LTI, you can't have both at the same time. I'm staying with Christies - not worth the hassle with other manufacturers. -Monte  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 02-10-2009 01:50 PM                     Jack, I need to re-iterate some discussion from another thread a while back (I think it was in discussion over the foreign-made equipment): Don't try to be penny-wise and pound foolish. Sure the Christies may cost a few hundred dollars more up front, but their proven track record results in a per-hour cost literally in pennies. That and the refunds and lost good will from ONE failure of an unproven or less reliable bulb will INSTANTLY wipe out any supposed savings from the cheaper bulb. Not to mention the cost of a new reflector. By the way Helios is the name of a book detailing the "China Syndrome" meltdown of a German Nuke reactor.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 02-10-2009 08:26 PM                        Christie/Osram have comparable pricing. Either one is good. The Helios might be very slightly cheaper. Dealer cost is NOT the same across the industry. Louis  |  IP: Logged Jack Ondracek Film God Posts: 2348 From: Port Orchard, WA, USA Registered: Oct 2002 posted 02-11-2009 11:32 AM                        OK... thanks for the comments. To refine where I think I was going with this: I'm not trying to save anything... just wondering if I could get more/better light from one of those newer bulbs, hours notwithstanding. Electrical savings or extending hours into the rediculous is not a consideration here. I'm not interested in risking more light against a greater possibility of violent bulb failure. Mark: I believe I was thinking about the Christies, but Helios came to mind first. Not really considering brand loyalty as much as whether these bulbs are any better than a standard old HS bulb, which generally works fine in my lamphouse.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-11-2009 12:18 PM                     Different lamp/reflector and lens combinations behave differently. There is no universal magic lamp for all applications (in terms of light). I've been doing tests for several manufacturers (LTI is NOT one of them). I've found one value priced lamp...ASL...that has a special version of their 4000-watt lamp called the 4202. As compared to a Christie CXL-40SC, the XM4202 will put out at least 20% more light when new. It has a pretty rapid burn-back and also a rather short life (about 800-hours before I noticed some flicker growing). However, it is also rather low-cost. The CXL-40SC is about 50% more expensive. So it really comes down to cost/hour and desired light. If you NEED the light (to achieve 16fL)...then that also has to be factored in. If you don't need the light then while the Christie may cost 50% more...the cost/hour in my typical systems is such that Christie remains cheaper to operate 39% cheaper, in fact. My testing on Christie's CDXL line of lamps though is showing tremendous light improvement (38% for the CDXL-45 over the standard CXL-40). Unfortunately, the CDXL-45 is about 38% more expensive than the CXL-40...so while you are getting the light, you are also paying for it. The CDXL-45 though is showing that it holds its high brightness VERY long..it decays about half as fast as the standard lamp. Nothing is easy on figuring out bang for the buck on lamp (unless you are only worried about hours). My suspicion is that the LTI Hellos behaves like the ASL 4202 series...they are quite a bit brighter initially, but have a rapid burn-back and have a relatively short life before visible artifacts show up. Steve  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 02-11-2009 01:02 PM                     quote: Steve Guttag but have a rapid burn-back and have a relatively short life before visible artifacts show up. Which draws the question: If these other manufacturers know that Osram and Christie have this attribute of duration, then one wonders why these other manufacturers try to follow suit so the can be more competitive in this end of the market spectrum? -Monte  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 02-11-2009 05:56 PM                        The brighter picture with rapid deterioration was normal on very old (1955=1965 Osram bulbs. Longer life engineering (which theatre owners wanted) was traded for reduced light output. "can't have one without reducing the other." Louis  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 02-11-2009 08:07 PM                     quote: Louis Bornwasser can't have one without reducing the other Ushio seems to have figured out how! Jack... you might also consider the Roberts Relelector upgrade. While the Big Sky reflector is great the Roberts unit may very well double your light. That'll give you indoor picture quality on an outdoor screen! Around 2500.00 or thereabouts plus installation. Mark  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 02-11-2009 09:07 PM                        What is the logic behind making a bulb that starts out bright and rapidly deteriorates? Are they supposed to be used in multiplexes, where the bulb can be moved to houses with progressively smaller screens as it ages? I suppose that this would work, although it would be labor-intensive. Does anyone actually do this? Obviously, the theatre owners want the lowest cost per hour of operation, but I would think that they would also want consistent light output without flicker over the life of the bulb. If the image is not sufficiently bright, then moving up to the next bulb size (or getting faster lenses or a different screen type) is always an option. Related question: what is the magic formula for determining the required lamp size for a given screen size? Presumably, this needs to take reflector speed, lens speed, shutter angle, screen curvature, and screen gain into account, along with several other factors.  |  IP: Logged Jack Ondracek Film God Posts: 2348 From: Port Orchard, WA, USA Registered: Oct 2002 posted 02-12-2009 01:08 AM                        quote: Scott Norwood Related question: what is the magic formula for determining the required lamp size for a given screen size? If you do a search under watts and square feet, you'll find some of John Pytlak's posts on the subject. Condensed: 5 watts per square foot on a matte white screen. Given that, everything else probably comes into play... screen gain, lens quality, shutter size, reflector condition & quality, etc.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 02-12-2009 03:16 AM                     Calculation almost works per this example: I worked in a complex that had a 33'x65' screen and we were shooting light from a 4500w bulb in an SLC-45 console going through a Christie P35GPS hitting this screen at 95 ft away. Thus as follows; 33x65 =2145 sq. ft times 5w/sq.ft.=10725 Divide by two for light loss for shutter blade swing per frame =5362.5 watts needed to light that FULL screen...and the pict was a little dim. House could have easily used a 6k bulb. Close estimate right off the top ... -Monte  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-12-2009 10:43 AM                     Given that 33 x 65 is not either 1.85 or 2.39 ratio...I wonder what you filled it with or was it a 2:1 job? I doubt it was a matte white...on a Christie system...you'd need a 14,500 watt lamp to hit 16fL on a matte-white (1.0) screen. It would be more than " a little dim." Steve  |  IP: Logged Dan Reiter Film Handler Posts: 74 From: Easton PA Registered: Jul 2002 posted 02-12-2009 12:02 PM                     Superior is still making the same 7K lamps that Jack mentioned up top, plus a High-Intensity version called the SX700001-I. Everyone has correctly identified the universal problem of more light vs long life. Without going into the details of lamp construction, the composition of as lamp built for bright light differs from a lamp built for long life. That is why Osram differentiates the two separate models now. The Superior lamps do sacrifice a little initial brightness for a longer lamp life. Jack has a sweetheart of a lamphouse, I know, as I built it! Special glass reflector with a great "F" ratio and the bonus of less heat in the gate. He is able to really provide a great show for his customers.  |  IP: Logged

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