This is topic Heat Filter Orientation in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Frank Angel (Member # 248) on 07-25-2002, 01:59 PM:
Ok, I finally got heat filters for an Orc 4500W lamphouse (they came with no instructions of course). The filters have a small paper dot on one corner of the class. Should I assume that the dot is an indication of how the glass is to be orientated in the holder? Dot towards the bulb, dot away from the bulb? Or doesn't it matter at all which way they are facing? If it would be better to talk to the manufacturer to get an answer, does anyone know if ORCON is still in business and if so, do you have a number I can call to get an answer.
And then if these filters do need to be oriented in a particular way, is there a way to tell by looking at the glass itself, because the other machine has filters with no marks on them at all and I have just been putting the glass into the holder any which way.
Any help would be appreciated.
Thanks,
Frank
Posted by Phil Hill (Member # 371) on 07-25-2002, 02:41 PM:
Identify the coated side of the glass by holding the glass so as to see a light reflected off the surface. The coated side goes toward the heat source (lamp).
Posted by Frank Angel (Member # 248) on 07-25-2002, 11:28 PM:
Thanks Phil; I did look every which way and BOTH sides look like they are coated, or at least there is nothing that distinguishes one side from the other - both have that coated look. I guess that's why they stick a dot on one side. Anyway, a guy at Strong said the dot goes toward the lamphouse -- although I got the feeling he was guessing the same as me (these are not Strong filters, unless Strong bought up ORCON). So the new filters that have the dot -- that's fine, but now I am anxious about the other lamphouse -- those filters have no dot an no distinguishing coating -- like I said, both sides look identical. How to tell which way they go? I suppose I could stick a heat probe in the gate and see which side reduces the temperature the most. Seems like that's a lot of work when the company could have easily etched THIS SIDE TOWARD LAMP if it were THAT critical.
Posted by Phil Hill (Member # 371) on 07-26-2002, 02:23 AM:
Hmmmmm...although I have never seen it, I suppose it is possible to coat both sides of the glass...why? I don't know.The idea is that the IR coating reflects the heat back away from the film without going through the filter "glass". In higher-power lamps (7kW, 10kW, 12kW, 15kW, 20kW), if the heat is reflected through the filter glass, it will overheat and crack the filter.
Most times the "hot" or lamp side is somehow marked. That is the dot or the arrow or the "Towards Lamphouse" sign.
Sorry, that's all I know.... 
>>> Phil
Posted by Jean-Michel Grin (Member # 1360) on 07-26-2002, 02:43 AM:
Just have a look on this service bulletin from Strong int. Maybe this can help you... http://www.strong-cinema.com/bulletins/service_bulletins/SB-0013.pdf Good Luck !
------------------
Jean-Michel Grin - Europlex Cinemas (Switzerland)
Posted by Pat Moore (Member # 380) on 07-26-2002, 07:54 AM:
Frank -- that dot should be towards the lamphouse. Most coated filters, if marked, would orient the mark towards the light source.That bulletin on our website might help. Touch the tip of a pencil to the glass surface. If the pencil seems to actually contact its image, that's the coated surface. If the image doesn't touch but looks to be about the thickness of the glass away from the pencil tip, that indicates the coated surface is on the other side.
Yes, Strong bought what there was of ORC back in '93, though what we really coveted was the Century Projector line.
Pat
Posted by Gordon McLeod (Member # 33) on 07-26-2002, 08:02 AM:
"coveted was the Century Projector line." And I always thought it was to get the ORC platter design
Posted by Frank Angel (Member # 248) on 07-26-2002, 01:42 PM:
Thanks guys. Dot to the lamphouse toward the lamp it is. As for the other lamphouse with the glass that seems to be coated on both sides and no mark, well, it's working fine, the film isn't embossing, so I am leaving it be.
Frank
Posted by Pat Moore (Member # 380) on 07-27-2002, 07:28 AM:
Gordon -- I'm hurt. You should know it was Optimax...
Posted by Gordon McLeod (Member # 33) on 07-27-2002, 08:56 AM:
pat said"Gordon -- I'm hurt. You should know it was Optimax"
That is good to know pat I am installing 8 of them of various vintages.
Since you like them so well maybe you can come up here and help align them
Posted by Richard Fowler (Member # 893) on 07-27-2002, 10:39 AM:
The last Optimax we removed from a client's multiplex his staff technician promptly chopped them apart so his boss would not get ideas of recycling them We did take three of them, threw out the interior parts, built an internal platform to hold a Cinemeccanica light module and reinstalled them in that client's circuit. He could not believe the 100% increase in light output, but then again technology and low bulb costs make this 25 year old concept not necessary.
Richard Fowler
TVP-Theatre & Video Products Inc. www.tvpmiami.com
Posted by Pat Moore (Member # 380) on 07-27-2002, 07:29 PM:
Gordon -- sounds like fun, actually, a little different from a normal day. Probably more frustrating, too.We have done a couple conversions to Horizontal lamps in those consoles using our standard Strong optics. What a difference. It is not a friendly conversion, however.
Pat