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Author Topic: Christie bulb spacer question Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 05-10-2005 04:36 PM                    We were contemplating getting these in order to rotate our bulbs (yep, it hasnt been done to this point) because we have the screw in type bulbs. I'm sure spacers or washers could be gotten at a local hardware store, but I cant find any specs on the "official" Christie spacers. Anyone know size? curcumfrance diameter etc. Also, would there be a problem with heat? I dont want them to melt or burn. Thanks!!  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 05-10-2005 04:37 PM                     The lamps normaly come with the washer on the lamp which is removed to rotate the lamp I am assuming that the lamp in question is the 1000 or 1600HSC  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 05-10-2005 05:00 PM                     Frank, Then best thing is NOT to rotate your lamps, just keep them and the reflector spotless. if you leave em alone and they will more than likely last longer. We have customers that typically get 12,000 hours from 2kw Christie lamps, note that they do have good lamp exhaust!. Not that running them to 12k hours is a good thing to do but none of these lamps ever get rotated and none have ever exploded either. Rotating lamps was necessary before the advent of the getter that is now inside of all xenon lamps manufactured since about 8 or 9 years ago. This getter attracts the vaporized tungsten so it does not deposit on the inside wall of the lamp and darken it. The quarter life(or half life) rotation was to allow the vaporized tungsten to deposit evenly on the inside wall so even illumination and heat dissipation through the quartz could be achieved. Thsi eliminated uneven stress on the envelope and reduced the number of lamp explosions. With very large lamps 4kw plus you might push a few extra hours out of em by rotating them. Some feel that this helps to keep the very heavy electrodes centered in the lamp so they don't end up sagging. All in all with todays lamps many techs including myself do not reccomend rotating lamps. The amount of life that can be gotten out of them without rotation and the inclusion of the getter speaks for itself. You definately need to get to a booth training seminar... As useful as F-T is this is not a training place. Those of us assisting with answers are sticking our necks out a bit in the liability department when we provide anssistence. You should also limit your liability at work until you become adaquately trained. Should someone be injured, or a film become damaged because of something you repaired you could be held liable... althougtn at your place it sounds as though they would just replace the dead person anyway . Perhaps the Kodak booth seminar would be the best one for you to attend since it is the most complete one going. You should also do the Dolby seminar around the same time. John P., can you provide Frank with some info on this..... Mark @ CLACO  |  IP: Logged Bevan Wright Expert Film Handler Posts: 176 From: Fountain Valley, CA, USA Registered: Sep 2003 posted 05-10-2005 07:52 PM                        Definitely agree with Mark, don't rotate them. Chances of creating problems (flicker, heat, focus, etc) is far greater than any benefit you will ever get.  |  IP: Logged John Walsh Film God Posts: 2490 From: Connecticut, USA, Earth, Milky Way Registered: Oct 1999 posted 05-10-2005 08:12 PM                     Not that I'm an expert in xenon bulbs, but I agree with not rotating them. You can see there's very little blacking at the top of bulbs today, so why bother?  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 05-10-2005 08:34 PM                     Not that it matters at this point in the thread, but chalk up another one in the "don't rotate" department. Overkill rooftop exhaust and Christie brand lamps is the real magic in getting phenomenal performance in a bulb anyway.  |  IP: Logged Frank Dubrois Jedi Master Film Handler Posts: 896 From: Cleveland, OH Registered: Mar 2005 posted 05-10-2005 11:23 PM                    The packing materials on the bulb packaging itself says "for maximum performance, rotate bulb at half-life" I dunno...just following instructions. Our bulbs typically start to dim (noticably) or flicker around 2000 hour mark. I didnt expect a miracle, but a little bit longer life would be nice if possible. Oh well..Thanks  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 05-11-2005 12:34 AM                     What lamps, lamphouses, and rectifiers, or consoles do you have there? Probably not enough from the blower either... The problem out here is that stupid HVAC techs don't take our 5000 foot elevation into account when specing them. It takes alot larger blower at this altitude to equal one at your altitude. I also find many of them running backwards. As for rotating..... Of course thay want you to go in and mess with the bulb... thats how they sell more new bulbs! Following "Lifes Instructions", not the manufacturers instructions, generally pays off in the booth........ Mark  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 05-11-2005 12:38 AM                     I remember when I used to work at EDW's and playing with 4K plus bulbs in our Christie Reference consoles that there used to be a spacer washer included in the box mentioning for the 180 degree rotation at half life - but never did any rotation due to the comments that Mark has mentioned (but had a parts bin full of these washers which came in handy for other uses). Later on, the washers were omitted in shipping bulbs with the recommendation for not doing any rotation. I've noticed that Osram and some other still recommend rotation at half life-guess an old habit is hard to break. -Monte  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 05-11-2005 08:18 AM                     my experience has been that rotating them improves the overall life span of the lamp as long as one does increase the current immediately after rotation I haven't had issues with flicker or the likes Also blackening is far more even  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 05-11-2005 08:42 AM                     quote: Gordon McLeod Also blackening is far more even I don't think any of us here see any lamp blackening at all any more on any manufacturers lamps.... literally none after 12k hours down here on Christies. What lamps are you using that blacken? Mark  |  IP: Logged Brad Allen Jedi Master Film Handler Posts: 688 From: Evansville, IN, USA Registered: May 2000 posted 05-11-2005 02:49 PM                     My Osrams blacken, always have. But I don't rotate. I found it caused problems. I may have to try a Christie. I'm lucky to get 2200hrs out of 2000w Osrams.  |  IP: Logged Brad Miller Administrator Posts: 17775 From: Plano, TX (36.2 miles NW of Rockwall) Registered: May 99 posted 05-11-2005 03:05 PM                     Brad, what kind of lamphouse are you using? The lamphouse itself, the exhaust and of course lamp brand plays a huge role. People just don't understand that even though certain combinations of equipment and lamps cost a little more initially, the extra expenditure pays for itself within the first year or two and then becomes noticeably less expensive to operate for the remainder of the cinema's life. You cannot beat the combination of a Christie SLC lamphouse, burning Christie bulbs and an overkill exhaust system. While any one of those three important items will improve a system's performance, I've yet to find any combination that beats the magic from using those three items together. (Sadly though I continually see Strong packages installed with all sorts of random bulbs and piss poor exhaust everywhere I look, which makes for a fairly lousy performance. )  |  IP: Logged Brad Allen Jedi Master Film Handler Posts: 688 From: Evansville, IN, USA Registered: May 2000 posted 05-11-2005 03:14 PM                     Ancient Kneisley Kni-tron Xenex Mod L2000. I've always suspected that the roof ventilation wasn't where it should be, but never could come up with anyone that could accurately check it. Once upon a time, I would get easily 5-6000hrs out of bulbs, but no more. Brad do you feel the same about the SLH lamphouse?  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 05-11-2005 05:22 PM                     quote: Brad Miller (Sadly though I continually see Strong packages installed with all sorts of random bulbs and piss poor exhaust everywhere I look, which makes for a fairly lousy performance ..any information on how much CFM's is required on exhaust to get life out of any bulb and also maintain excellent presentations? SLH consoles, isn't that the "Reference" consoles? If it is, that is one SWEET console. thx-Monte  |  IP: Logged

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