Film-Tech Forum ARCHIVE: CFS Console Light Output Problems-PLEASE HELP!

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Posted by Aaron Sisemore (Member # 145) on 08-21-2000, 02:32 PM:

I am working with a rather large fleet of CFS SX2000 and SX4500 consoles (vertical xenon with the diagonal mirror at the top), and with all the tweeks and tricks that I know cannot seem to get any real light output out of any of them.

I can get retina-burning brightness Strong consoles and lamphouses, and fairly nice light from Christies, but the CFS' are almost impossible to get anything with. One of the screens is running a 3000w bulb @ 100A throwing to a 35' wide screen and the best I can get is 4 footlamberts, with some of the 2000W screens (all smaller size screens) I have been able to get 8-10 FL at best, and thats on the ones with the real short throws usually.

I am sure that there is some lamp/projector alignment issue involved, but How does one align the light chain in a vertical lamphouse with the diagonal mirror? Obviously the Strong/Christie "string and weight" method isn't gonna work here... Or is it just impossible to get 16FL out of these things?

I know CFS is generally crap but I am stuck with a LOT of these consoles and no chance for changing them out or upgrading...

Any help would be wonderful!

Aaron

http://www.cinema-west.com

Posted by John Walsh (Member # 168) on 08-21-2000, 03:01 PM:

I know this is not really what you want to hear, but those lamphouses with 45deg mirrors have always been poor. In other words, I think you have probably got as much light out of them as you are going to ever get. We used a laser-beam type lamp aligment fixture (since rods or strings won't work on a 45deg angle) and it was still poor light (although it was evenly lit.)

I adjusted ORC lamps (with the same design) and never got them really "right." It took a long time for me to finally realise that the 45deg idea just sucks.

Posted by John Pytlak (Member # 331) on 08-21-2000, 03:03 PM:

Maybe Pat Moore can help, as this design is similar to the ORC OPTIMAX consoles that became part of Strong. Laser alignment from the lens position should be possible with the correct jigs. We have a pair of the ORC consoles, and agree alignment can be challenging. Likewise, we are constantly fighting "candlelight flicker" from the unstablized plasma of the vertical lamp arc. The design is very efficient for reducing heat on the film from IR, however.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Eastman Kodak Company
Research Labs, Building 69, Room 7419
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com

Posted by Brad Miller (Member # 2) on 08-21-2000, 03:12 PM:

Yup, laser is your only real hope for aligning those. It's Cinemark, right? I told them back in the late 80s they shouldn't be purchasing those junkers, but they had some big (probably under the table) "deal" going and quality wasn't the issue. At least they finally wised up and started purchasing Christie and Strong lamphouses.

BTW, 100amps for a 3000 watt bulb? That sounds a little low.

Posted by Pat Moore (Member # 380) on 08-21-2000, 03:38 PM:

Aaron (and thanks for the faith, John);

I hate to bad mouth products but I've never been happy with vertical system performance. The geometry of bouncing a condensing cone of light off a flat surface just doesn't work well.

Assuming reflective surfaces of the collector and mirror are all in good shape, there are a lot of mechanical issues that are best checked with a laser alignment tool from the projector side. That will help verify the optical path's centerline and the adjustment of that 45-degree mirror. That will at least tell you if the center of the reflector is in the right place.

After that, you're left to assume that the collector's optical centerline is in the proper position, and that's anybody's guess.

Way-back-when I did this stuff for real, I had a fixture that fit into the collector to give you a return beam of the laser. If that return path was the same as the originating path, things were in good shape. If it wasn't, you could shim the collector and its mount as required to get it there. At least then, in theory, all the centerlines were correct and the system was optimized as well as it could be.

Without at least a laser, it's trial and error and anything but fun. I usually ended up moving everything around while running white light to get things as good as I could.

If I can throw any more light on the subject let me know. (Sorry...)

Posted by Jason Burroughs (Member # 68) on 08-21-2000, 06:18 PM:

Brad is right, the designs with the folding mirror waste a LOT of light. CFS has a BIG problem with the folding mirrors (45deg mirror) either flaking is coating off or cracking, Also their refectors are very prone to flaking thier refective coating off leaving just a dull metal surface, The last Cinemark that I worked at they over lamped the auditoriums (using 4500 watt bulbs on all houses except the biggest ones which got 7kw lamps,) and we got 22ft+ lamberts on most of the screens, yes that was overkill, but it was nice to see a cinemark with a decent amount of light on the screen. Usually the alignment of the mirror itself isn't too far off unless the unit has just been moved, must make sure all the reflective parts are in tip to shape.

Posted by Randy Stankey (Member # 64) on 08-21-2000, 07:42 PM:

I have burned a 3k lamp in a LSX-4500 lamphouse. 100 amps is about par. It will be a little dim if you have a big screen.

I'm assuming you have things like the lamp focus, reflector centering and projector alignment properly adjusted. If you haven't, check those first.

Second, there are a couple of different reflectors for that LH. There is a different one for 2.5K, 3K and 4.2K. The power supply is essentially the same, except for the obvious things and the rest of the console itself is exactly the same. Find out what reflector you have. That'll affect your light output.

Also check the dichroic (folding) mirror. They have a tendancy to crack, craze, warp, peep and anything else you can think of. A crappy mirror won't reflect light even IF your lamp is putting out. Those mirrors have been a big problem for many of our theatres. As you can imagine, the bigger the lamp, the faster they go. (More heat)
They can get out of line, sometimes, too. Not often, but if somebody replaced the mirror and did a crappy job, it's a possibility.

Posted by Mark Huff (Member # 480) on 08-21-2000, 10:49 PM:

OK first off you are correct when you say you get about 3 footlamberts. The CFS console has to be the worst console out on the market for light output. First off I used a 7K lamphouse and I only got 3 footlambers out of it for a long time. I had to crank the bulb way down in the reflector. OK. Are you using a Christie bulb? If not I suggest you may want to try them they work pretty well with Rentec junk. Be sure to get short cable bulbs though. Secondly have you checked all of your diodes. Rentec will tell you every time you call them in a sarcastic voice "Have you checked your diodes" then their next favorite phrase is, what is the amprage and voltage on your machine reading. Then followed by well maybe your machine has the wrong amp and volt reading. Check it from the DC lines coming off the bulb at the bottom. Then they want to know how much AC ripple do you have coming off of your rectifier. Now they deny all aspects of having sold your theatre a piece of shit lamphouse.

When all they have to do is say I'm sorry sir none of our lamphouses will give you good light unless we want to spend money and produce quality machinery. But I guess that would be the smart thing to do.

I am sorry for ranting about CFS but the quality they produce is just way too low for my time spent repairing these junkers.

Brad I would like to see a review on this lamphouse by someone. I think that even Joe couldn't have made a false implication of these machines.

Posted by Tim Reed (Member # 137) on 08-21-2000, 10:57 PM:

Assuming the projector's centered on the lamphouse opening... I just loosen the reflector screws, turn everything on, and move that sucker around until the hole in the reflector's centered in the lens holder shadow on the porthole. Pretty quick and easy, BUT (and here's the catch)... the folding mirror has to be true, and at an exact 45 deg. angle to the front of the console, or you're sunk.

------------------
Better Projection Pays!

Posted by Aaron Sisemore (Member # 145) on 08-22-2000, 02:11 AM:

Hello all:

Thanks for the replies, I figured a laser was gonna be necessary to do the alignments with...

Yes, the reflectors on these things are 100% pure SHIT. My DM and I have done our share of polishing and buffing and cleaning the pitted, dull and fogged main (salad bowl) reflectors and I have replaced the 45deg mirror on the 3k console TWICE, after the first two stripped themselves of their reflective coatings, CFS claims to have corrected the problems with the reflective coating stripping with the new mirror assembly that doesnt need a cooling fan... but there still isnt enough light...

As for bulbs, we are running mainly ORC/PerkinElmer and Osram, and will be replacing all the ORCs as they die with Osrams, the Osrams have been VERY good with these lamps as far as light output and striking goes.

As far as diodes go all of the diodes are good, I am getting full current and no abnormal flickering...

Maybe I can do the review of the CFS console and the NSP-3 platters...

Thank you all again!

Aaron

Posted by Gordon McLeod (Member # 33) on 08-22-2000, 08:26 AM:

Ultra flat makes a good cleaning material for reflectors
I machined 2 disks out of plexiglas one fits the top of the collector exactly the other the bottom hole. Each has a pin hole in the centre. I mounted a laser in the centre of the lens mount and shone it back and just kept adjusting till it shot down through booth pinholes.
I had tried the laser I bought from ORC that mounted in the hole in the bottom of the laser but found that the reflector hole wasn't machined true so the laser would shine on different angles upwards defeating the purepose
This worked on the old orange ORC' consoles so it might help on the CFS
Turning the disk for the top of the reflector was a pain in the butt as well

Posted by Michael Pace (Member # 553) on 08-22-2000, 08:56 AM:

I sympathise with you on having CFS/Rentec consoles. I am looking after 4 LSX 2500 and 2 LSX 4500 consoles and I find them the most difficult of brutes to deal with. I do not have a light meter available so I simply adjust them for the best looking light on the screen. This is not an easy task as the adjustment screws are so coarse in their operation that it becomes difficult to find the exact focus position and it does not help that the whole mechanism is floppy. Also be careful as it is possible to acheive focus in a second position that appears to give good light but you soon realise that it is simply not right.

Also the mechanism will settle with the vibration of the console and will need to be adjusted a second time. And why don't the holes in the cabinet line up with the adjustment screws?

I have found that the rectifier on the LSX 4500 consoles do not step the current in steps when adjusting on the course/fine tappings. With the lamp burning as approximately 130amps the next step should increase the current by 4 amps or so but it takes it out to 160+ amps. I have wondered if this is an artifact of having 50Hz supply in Australia versus the 60Hz in USA. I should point out that this does not happen on the LSX 2500 consoles.

I am using Ushio UXL-SC25 and UXL-SC40 xenon lamps, I had to have adaptors made to make them fit. Never had much luck with the ORC lamps as they became unstable too fast.

Another item to watch for is seized blower motors. Why anybody uses sleeve bearings now days is beyond me.

Regards,

Michael.

Posted by Pat Moore (Member # 380) on 08-22-2000, 07:43 PM:

Michael -- I visited Townsville for your theatre, I think, about three years or so ago. Great little town, wouldn't have minded spending a little more time there. You must be at the Reading Theatre there, right? Just interesting when I come across places I've been...

Posted by Aaron Sisemore (Member # 145) on 08-22-2000, 09:02 PM:

This afternoon I spoke with T.C. Ostin at CFS and he gave me his methods for "getting perfect light from a CFS Console" His recommendations included:

1. With no lens in, open the main lamp door, loosen the 4 bolts that keep the bowl reflector locked in place, then *defeat the interlock, strike the lamp* and slide the reflector around until you get a good set of 'rings' around the black dot in the center of the screen. If you can't get a good set of rings then you can shim the reflector mounting plate with old aperture plates or THIN washers until you get a satisfactory image.

2. Remove the anamorphic from the scope lens. Using the prime lens and a scope aperture plate, focus the bulb untuil you get a hot spot with 4 even dark corners (If you cant get 4 even corners, you need to repeat the reflector-moving part mentioned above until you do.) Once you have all 4 corners even, then focus for the most even light all across the picture. Replace the anamorphic and double-check the light evenness with flat.

T.C. Says the bowl reflectors' coatings degrade both with time and high heat. He says that some but not all of these reflectors can be recoated. Why then do Strong reflectors not degrade? Christie reflectors do go yellow after a time, but even then they are still viable... To quote Joe: This Blows.

Step #1 sounds both dangerous and stupid to me, maybe its just the way I am, even though Tim seems to have done the same...

I am awaiting the price on the laser alignment rig that CFS uses in the manufacture of the consoles...

Aaron

Posted by Brad Miller (Member # 2) on 08-22-2000, 11:34 PM:

I've had to do many an alignment with the doors open. I'm ultra careful and never 100% "relaxed" while doing it, but it can be done and it's not too dangerous. However if you are not comfortable enough with it...make someone else do it! Also, wear your protective gear! (I also have this little habit of standing behind the console before I strike the lamp like that.

)

And now for the "duh" part...don't look at the light!

Posted by Randy Stankey (Member # 64) on 08-23-2000, 05:56 AM:

You don't have to have the door open to do the reflector alignment. You can loosen the bolts, close the door and strike the lamp. To move the reflector, grab onto the bottom of the "rack" mechanism and slide it around. Wear your xenon lamp changing gloves to protect yourself from touching any wires, etc. When you get it right, shut down and let it cool for a while. Then you can open the door and tighten the bolts again.

I've had to do this about a dozen times 'cuz we had to change out all our reflector bowls. The reflectors and mirrors all needed to be replaced in some of ours. I had to figure it out by myself (ourselves)
It's a real PAIN getting the dichroic mirror out of those damn things. You might have to take the whole console apart to do it, depending on what 'flavor' of mirror it is.

Posted by John Pytlak (Member # 331) on 08-23-2000, 05:59 AM:

Brad said: "And now for the "duh" part...don't look at the light!"

The light output of a xenon lamp has significant amounts of ultraviolet energy. Looking directly at the arc for even a brief instant can cause permanent retinal damage to the eyes. Direct exposure to the strong ultraviolet can also cause skin damage, similar to severe sunburn.

Posted by Tim Reed (Member # 137) on 08-23-2000, 07:56 AM:

quote:
Step #1 sounds both dangerous and stupid to me, maybe its just the way I am, even though Tim seems to have done the same...

You mean you have to be sane for this job?!?!!

------------------
Better Projection Pays!

Posted by Greg Mueller (Member # 17) on 08-23-2000, 08:24 AM:

If your need to do a lot of alignments you can get a collimating tool out of Sky & Telescope magazine for $100 or less. A quick trip to a machine shop with get you an adapter that will adapt it's 1 1/4" size to your lens size. Collimating is done regularly by amateur astronomers to make sure their optics are lined up, especially on the Newtonian design, which is basically what you're talking about. It won't help you with the spherical or parabolic reflector but it will get you diagonal and bulb lined up.

------------------
Greg Mueller
Amateur Astronomer, Machinist, Filmnut

Posted by John Eickhof (Member # 323) on 08-26-2000, 09:17 PM:

I have installed several hundred CFS SX & L
consoles through the years, I have had no problem achieving nominal light output on about 90% of them. The wakest area is the 45'
mirror assy, if it gets mis-aligned in shipping or by bulb explosion your light output will suffer dramatically. The layman can check it's relation to the projector head simply with a ruler and protractor. It MUST
be 45' in relation to the FILM, the reflector is fully adjustable by loosening aformentioned bolts and sliding around.
The main thing to remember, is to move the reflector slightly then check light, I also recommend wearing welding mask or goggles so you can view the light as you are doing this as well as put SPF25+ sunscreen on your hands and face and any other exposed skin! (I usually wear gloves and long sleeves) Have fun!