Film-Tech Forum ARCHIVE: Drawing of reflector Strong Ultra 80

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Posted by Jan Eberholst Olsen (Member # 10133) on 09-19-2017, 06:53 AM:

I am looking for a drawing of the mirror/reflector in the Strong Ultra 80 lamphouse. Preferably a Strong factory drawing or similar.

Posted by Jim Cassedy (Member # 4115) on 09-19-2017, 02:50 PM:

There are two Ultra 80 manuals in the "warehouse" section of
this website. The manuals have a couple of line drawings that
show the general shape of the reflector, as well as a couple
of photographs of the interior of the lamphouse which show the
reflector- - but I'm not sure these are exactly what you're
looking for or have enough detail for your purposes.

Posted by Mark Gulbrandsen (Member # 72) on 09-19-2017, 04:35 PM:

You wold have to contact Optiforms as they made the reflector for Wrong. The guy who runs OPtiforms is a really nice guy, but I am not sure he will give out proprietary design info like that. Wrong certainly wouldn't give it out.

http://www.optiforms.com/electroforming/

Mark

Posted by Jan Eberholst Olsen (Member # 10133) on 09-20-2017, 01:35 AM:

Thank you very much for the reply. The Optiform route seems the way forward. I am looking for a matched pair of mirrors as a future back up. I was told that the metal mirrors would degrade over time, even without use? They may be in stock for 10 or 20 years (we are a film archive and would like to screen films as long as possible). If that is true, my option would be to get a custom made mirror made out of glass instead

Posted by Sam D. Chavez (Member # 1841) on 09-20-2017, 02:05 AM:

There is way more to it than just duplicating the metal mirror shaped size in glass.

Let me count the ways...

Very expensive to make in small quantities and to hit the desired color temp at all, much less in a matched pair is asking a lot. Doing the same in glass is even harder to do. There is the matter of IR and heat that passes thru the glass and heats the back of the lamp and its wiring. Super 80's were not designed with glass mirrors in mind.

Roberts Film Service in Canada has a stock of glass reflectors for a number of lamphouses. They might be able to help.

You would be better off to find a pair of Kinoton lamphouses that already have glass reflectors and take it from there.

Posted by Jan Eberholst Olsen (Member # 10133) on 09-21-2017, 03:37 AM:

Sam, thank you very much for your input.

I have thought about the Kinoton way, but I really like the even light output from the Strong lamphouse, the beam spreader for 70mm and the nice manual douser. I can get a European specialist company (Weule) to make a glass reflector, but I am concerned what will happen inside the lamphouse heat wise. We are thinking of removing all electronics from inside the lamphouse, and just use a DC igniter from Kinoton. The rest of the electronics could be outside of the lamphouse (underneath the table on the NorelcoAA). If there is "nothing inside" except the DC igniter, does it matter if we change the design? We will measure the air flow inside the lamphouse, to make sure the bulb and mirror will get the correct cooling (we now use a Pabst fan when the original one stopped a few years back)

Will a metal mirror loose its reflecting capability when stored in an office environment for lets say 10 - 20 years?

A glass reflector can be delivered with the same color temperature (or at least they say they can), which is very important especially for change-over operation of black and white movies. If the glass reflector is more proven to maintain its reflection capabilities lets say 50 years from now, it may be the right way forward (but a difficult and expensive one).

Posted by Steve Guttag (Member # 268) on 09-21-2017, 09:12 AM:

Wait a minute. You want the Ultra-80 reflector (same reflector they have been using since the X60D days, by the way...the difference being they want from a "potted" reflector to a flanged one) because of its evenness as compared to a Kinoton? Have you honestly compared the two? It isn't going to be a very close call. I used a LOT of Strong lamphouses over the years and while I did like them, I wouldn't put them favorably against a Kinoton in any department (evenness included). The metal reflectors, if you ever used a string/laser to check were a bit wavy right from the factory.

Posted by Mark Gulbrandsen (Member # 72) on 09-21-2017, 11:40 AM:

quote: Steve Guttag
I wouldn't put them favorably against a Kinoton in any department (evenness included).

Well, a Christie SLH goes up very favorably against the Kinoton. In fact at the Egyptian Theater they started out with a pair of Kinoton's and could not get enough light on the screen. They switched to a pair of SLH's which had considerably more light and they remain there to this day. So look at the Christie reflector used in the SLH, not the Strong. It is also made by Optiforms.

As for the coating degrading, Optiforms could probably answer that question. It is possible the rhodium coating might cloud up if left exposed to normal atmospheric pollution. But if the mirrors were stored in say a nitrogen filled container then deterioration might be zero.

By the way, I have replacement Arriflex camera shutters here which have a mirrored surface, and there is no degradation of those surfaces. One is at least 40 years old.

Mark

Posted by Robert Brunson (Member # 10216) on 10-16-2017, 06:46 PM:

Hello all,

Rob Brunson from Optiforms here - Yes, we pretty much provided all of the electroformed dichroic coated reflectors, and many other downstream optics, for most of the projector manufactures, Ballantyne/Strong, Christie, Keisley, Cinemeccanica, Eprad, Texas Instruments, as well as a lot of the retro reflector sets used in the early part of Digital. We still offer AMR (Aftermarket Replacements)versions of all of the reflectors. Regarding the coating, a lot has changed over the years with regards to coating materials and coating designs. Our current DCC (Dichroic Cold Coating)is far superior to the early stuff. DCC coated reflectors have a porous coating, especially the older ones, and they do take on moisture over the years, and when fired up with a nice hot Xenon source it can be detrimental to these older coatings. As a few had posted earlier, these electroformed DCC coated reflectors are designed to maximize the %R in the visible region, while absorbing the IR and UV. This creates a lot of heat being soaked into the reflector, so it needs to be cooled properly. Glass reflectors obviously reflect the same light, but transmit the unwanted light, typically meaning a cooler running reflector, but you also need to get that heat exhausted. Basically two different types of designs, but designed to do the same thing, illuminate a screen. There are pros and cons to both types of reflectors, glass and electroformed.

Posted by Mark Gulbrandsen (Member # 72) on 10-26-2017, 04:01 PM:

I did have a lot of Xenex 2 mirrors coating fail at first, so I guess that had to be the old coating. Those were usually replaced under warranty. Ditto for 4 to 6kw Christie SLC mirrors. No matter how much air you tried to move through the console, the coating would still burn on both the mentioned reflectors.

Mark