Film-Tech Forum ARCHIVE: Best Bulbs based on wattage

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Posted by Michael Rourke (Member # 1142) on 02-13-2004, 04:28 PM:

Okay we all know Christie's and Osrams are the best, We know that Perkin Elmers are shit, and LTI and Superior Quartz are somewhere in the middle trying to gain a good rep.

I have all Christies in 2K, 3K and 4.5K SLC lamphouses. My 2K's are performing marvelously, but the 3K and 4.5K get to warranty and not much more before the envelope darkens and I get a noticeable flicker. I asked a Christie tech once and he said that Osram makes the best 3K's [Eek!]

I won't mention his name, but I appreciate his honesty.

So I am interested in what make AND wattage you are having success with, I'm sold on Christie's for 2K, but I am interested in stories about 3K and 4.5K.

Thanks

Posted by Brad Miller (Member # 2) on 02-13-2004, 04:31 PM:

I have yet to see any bulb that outperformed a Christie in a Christie SLC. I have also been seeing lots of issues with Osram bulbs over the last few years. If you want to give another bulb a shot, check out the Superior Quartz bulbs.

I am interested in knowing how much exhaust you have being pulled out of those lamphouses. That sounds like the problem to me.

Posted by Michael Rourke (Member # 1142) on 02-13-2004, 04:44 PM:

I tried one LTI and one Superior Quartz 3K and both were pulled before warranty. The LTI just flickered and the SQ envelope turned orange. That same SLC now has a 3K Christie in it and is around warranty and looking good.

The exhaust isn't bad, but it isn't great either, the fans are plenty powerful but all 7 exhausts run to one duct in a T shape so there can be some reverse pressure down the line.

Brad, do you know what your lamphouse cfm is? I don't want to start the overcooling debate all over again with the others, but since you get good performance and you are over the recommended cfm that is good enough for me.

Posted by Aaron Sisemore (Member # 145) on 02-13-2004, 04:50 PM:

I am happy with SQ, Christie, Osram, and LTI bulbs thus far. (recently we have been using exclusively LTI for 1-3k and SQ for 4K+)

FWIW, of the three bulb explosions I have experienced in my career, two were Osram (2K and 3K) and one was LTI (with less than 200 hrs)

The rest of my 'early' bulb failures were seal failures and happened pretty much evenly between Osram, ORC/PE, and the dreadful Chinese bulbs I have had the unfortunate experiences with.

-Aaron

Posted by Brad Miller (Member # 2) on 02-13-2004, 05:21 PM:

quote:
Brad, do you know what your lamphouse cfm is? I don't want to start the overcooling debate all over again with the others, but since you get good performance and you are over the recommended cfm that is good enough for me.

Here is what I did at one location which has the best bulb performance...

On the SLC 2K-3K units I have 900CFM blowers (slightly less in the chamber, even though the duct is almost straight up). The units running 2K lamps have the speed turned down a little bit.

On the SLC 4K-6K units I have 1100CFM blowers, with the speed on the 4K lamps turned down a bit too.

And most importantly...I have a 20 minute time delay circuit wired up to the exhaust switch. This way if the projectionist is in a rush to get out of there at the end of the night, when the booth is powered down, the exhaust continues to run for 20 minutes. Bulb cool down is very important to long bulb life.

All are Christie SLC consoles and I have a variety of lamps I have been testing in them. The Christie lamps outperformed all others in sheer life, but what I found was quite amazing. During the installation of the exhaust most of the bulbs were at warranty or past it (a couple of them WAY past hours and badly flickering and having ignition problems). After the exhaust was installed and ran for a few days, all of the bulbs settled down. On those bulbs that were substantially over warranty there were no more ignition problems and the arc flicker literally went away. Yes, these were bulbs I was concerned about removing and disposing of, still performing wonderfully. At this point I am dying to see just how many hours I CAN get out of the bulbs. The only unit that is not getting ridiculous hours is the 6K lamps. Looking back at it, I wish I had've bumped up the CFM on that one a bit more, but the theaters are still getting incredible life as it is.

To give credit where credit is due, Mark Gulbrandsen was the one who preached about overspec'ing the exhaust CFM. I've done this CFM overspec'ing at a couple of theaters now and he was RIGHT! The difference is phenomenal and the entire cost of the blowers, ducting work and electrical work will pay for itself in one year's time on bulb savings alone.

Posted by Jack Ondracek (Member # 1466) on 02-14-2004, 01:47 AM:

Brad's pulling a couple hundred cfm more than I am... guess I'll give it a try... maybe add a little nitrous to the fuel.

I wonder though... what kind of airflow are the manufacturers talking about, given a particular wattage, when they warn against overcooling. I don't think I've ever seen actual cfm numbers.

Posted by Jason Thode (Member # 1854) on 02-15-2004, 02:53 AM:

Brad Is right about no other bulb being able to out do a Christie. In one of my Christie SLC lamphouses we had a 2k bulb from when the theatre first opened, still going strong. When I checked the sheet it had 9500 hours on it, the bulb is also 3 years old. If your going to buy a bulb buy a Christie and no other. (this add was not in anyway paid for by christie).