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» Film-Tech Forum   » Operations   » Film Handlers' Forum   » Hexagonal prints? help b4 it falls of the platter!

   
Author Topic: Hexagonal prints? help b4 it falls of the platter!
Andy Muirhead
Master Film Handler

Posts: 323
From: Galashiels, Scotland
Registered: Dec 2000


 - posted 01-02-2001 06:26 PM      Profile for Andy Muirhead   Email Andy Muirhead   Send New Private Message       Edit/Delete Post 
Hi everyone, this is my first time posting although i have been reading you postings for some time.

My problem is this: for some time now some prints have started to lose shape on the platter when feeding out, so by the time it gets to the last reel, they are hexagonal. Sometimes they even go triangular so by the time the platter has speeded up to pay out, momentum has shifted the film, and eventually they fall off the platter. Emergency measures cause us to tape about 8 plastic film cores round the print to help keep shape. This solves the problem short-term but is dodging the issue!

Why then? We have CFS platters. This prob only ever occurs in our No4 Proj room where there is no extraction from lamphouse and can get hot as hell. Is heat or humidity a factor? We do move the print from 4 to 2 and the prob still occurs but not as extreme. Could the film be wound too tightly on the platter on takeup?

oh wise people of film-tech enlighten me, as we now have two prints affected this way (Coyote Ugly + Unbreakable - sorry cant remember if they are UK or US prints as i am at home juxt now!)

Happy New Year to you all,
Andy Muirhead

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Brad Miller
Administrator

Posts: 17657
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 01-02-2001 06:31 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
Besides the obvious problem of CFS platters, I'd definitely say if it is getting hot as hell in that booth that the humidity in there is at an extreme low. There are many tips to raise humidity and John Pytlak is probably the best man to answer such questions. I'm sure he'll be along in the morning.

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Paul G. Thompson
The Weenie Man

Posts: 4718
From: Mount Vernon WA USA
Registered: Nov 2000


 - posted 01-02-2001 06:49 PM      Profile for Paul G. Thompson   Email Paul G. Thompson   Send New Private Message       Edit/Delete Post 
Andy, I have to agree with Brad. In addition to being hotter than hell in the booth, it might also be dryer than a popcorn fart as Brad pointed out. And, yes... the CFS platters don't help the matter any. If you are worried about the platter throwing the print, make a bunch of stick-um puckeys out of old preview cores with inside-out masking tape and put them on the platter so they will prevent the print from shifting to the point of no return. I had to do that many times..


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Gordon McLeod
Film God

Posts: 9435
From: Toronto Ontario Canada
Registered: Jun 99


 - posted 01-02-2001 06:52 PM      Profile for Gordon McLeod   Email Gordon McLeod   Send New Private Message       Edit/Delete Post 
You need to get a humidifier in the booth

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Darryl Spicer
Film God

Posts: 3250
From: Lexington, KY, USA
Registered: Dec 2000


 - posted 01-02-2001 07:22 PM      Profile for Darryl Spicer     Send New Private Message       Edit/Delete Post 
Definetly a humidity problem and it doesn't take much heat to cause this. The humidifier is a good idea if nothing can be done to help cool the booth. The only problem with humidifiers and extreem heat is the moisture tends to build up in the air and settles on projection parts and sound boards over night when the booth cools down. this sometimes can lead to board failures and rusting of equipment. Also the excessive heat is not good for your equipment either. You may want to look into seeing if the booth can be air conditioned or see if the exhaust from the lamphouse can be vented out of the booth. In the long run it will save on equipment failures that could possably add up to more than what it would cost to vent out the heat.

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John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000


 - posted 01-02-2001 09:39 PM      Profile for John Pytlak   Author's Homepage   Email John Pytlak   Send New Private Message       Edit/Delete Post 
Sounds like a classic case of "spoking", caused by excessive film curl when the humidity is too low. At very low humidity, the gelatin film emulsion shrinks, causing the film to curl (cup) in toward the emulsion. Severely curled film is difficult to wind evenly, and may take on the shape of a polygon, rather than a circle.

Kodak recommends maintaining projection room humidity between 50 and 60 percent RH. Measure the humidity with an accurate digital humidity gauge or a sling psychometer. I'll bet your humidity is below 30 percent RH. Use an evaporative humidifier to add moisture to the air. Don't use an ultrasonic or misting humidifier, as the salts that are in the water will be spread throughout the box (booth).

A free-hanging strip of film should lie nearly flat, with only a slight cupping toward the emulsion ("positive curl").

------------------
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 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com

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Randy Stankey
Film God

Posts: 6403
From: Erie, Pennsylvania
Registered: Jun 99


 - posted 01-02-2001 10:45 PM      Profile for Randy Stankey   Email Randy Stankey   Send New Private Message       Edit/Delete Post 
Also, once a print gets "dried out" it will take a heck of a long time for it to get back to normal.

Do the hanging film "thingy" like John says. It doesn't cost you anything and it'll tell you a lot.
Cut off a piece of film from an old trailer about 1/2 a foot long. Tape it to the wall near the platter. If you look at the film at it lies against the wall, the image will be right side up and the sound track will be on the left. (This way the emulsion is away from the wall and it will curl "out" from the wall.) Just one piece of tape at the top and let the bottom hang free.

I'll bet in a couple of days that piece of film will be curving way up. I had one piece of film curve up into a letter "J". If it does that, you had better turn the heat down and get ahumidifier... pronto!

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John Walsh
Film God

Posts: 2490
From: Connecticut, USA, Earth, Milky Way
Registered: Oct 1999


 - posted 01-02-2001 11:11 PM      Profile for John Walsh   Email John Walsh   Send New Private Message       Edit/Delete Post 
While you are looking into the low humidity, you can take a lenght of scrap film, wrap it around the outside diameter of the feature film, cut and splice it to match. It will hold the feature in a round shape while running.

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Aaron Sisemore
Flaming Ribs beat Reeses Peanut Butter Cups any day!

Posts: 3061
From: Rockwall TX USA
Registered: Sep 1999


 - posted 01-03-2001 01:37 AM      Profile for Aaron Sisemore   Email Aaron Sisemore   Send New Private Message       Edit/Delete Post 
Get FilmGuard... It will help dramatically.

In defense of CFS platters (since we have a LOT of them) I have only seen a CFS platter throw a print when one of the rollers between the motor and disc had come loose and cause severe vibration , causing the print to literally shake off the deck., besides that I have NEVER had a CFS platter toss a print... I have had AW3's (A platter I prefer over the CFS hands down) that would launch prints like crazy, until I timed them to the Film-tech specs and have never thrown a print since with an AW3...

Aaron

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Dick Vaughan
Phenomenal Film Handler

Posts: 1032
From: Bradford, West Yorkshire, UK
Registered: Jul 2000


 - posted 01-03-2001 02:19 AM      Profile for Dick Vaughan   Author's Homepage   Email Dick Vaughan   Send New Private Message       Edit/Delete Post 
Andy

It's not only the condition of the prints because of the low humidity you should worry about. I am sure that your local health and safety inspector would take a very dim view of running without extract on the lamphouse.

It might be worth talking to your cinema manager / owner about working conditions.

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John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000


 - posted 01-03-2001 07:33 AM      Profile for John Pytlak   Author's Homepage   Email John Pytlak   Send New Private Message       Edit/Delete Post 
Dick Vaughan said: "It's not only the condition of the prints because of the low humidity you should worry about. I am sure that your local health and safety inspector would take a very dim view of running without extract on the lamphouse."

I agree with Dick. Even with today's "ozone free" xenon lamps, a small amount of ozone may be generated by the high voltage ignition and the ultraviolet energy. Ozone is needed in the upper atmosphere, but is NOT good to breathe. Lamps should be vented to the outside air. As noted, unvented heat from the lamp will make the projection room hot and excessively dry.


------------------
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 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com


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Sean McKinnon
Phenomenal Film Handler

Posts: 1561
From: Peabody Massachusetts
Registered: Sep 2000


 - posted 01-03-2001 11:09 PM      Profile for Sean McKinnon   Email Sean McKinnon   Send New Private Message       Edit/Delete Post 
At my old theatre (Rachels theatre) they just have blowers on top of the strong superlume-X lamp houses they say the ventallation ducks are collapsed and its the mall that has to fix them. It never really caused any problems but in Massachussetts IT IS AGAINST THE LAW! (but it was also against the law for them to let me project at 16!)

------------------
I love to smoke I smoke seventhousand packs a day and I'm never F*&ing quittin!-- Denis Leary

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Erik Schill
Film Handler

Posts: 38
From: Rochester, NY, USA
Registered: Nov 2000


 - posted 01-06-2001 02:53 PM      Profile for Erik Schill   Email Erik Schill   Send New Private Message       Edit/Delete Post 
Don't feel bad Andy, we have the same problem at my theatre, probably even worse, BUT, even with knowing the problem we are too damn cheap to fix it, we have like a $5 budget for the booth, god forbid if a lamp blows, cause you know we don't have spares laying around. We have these sticky pad things called TECO 1-800-863-8326, they are like $3 a piece (which we had to pay for out of our pockets) and they work really good, unlike cores these stay on the platters, so we use them, and a shit load of cores too, and we have not had a thrown print in a few months, and when that did happen it was because the idiot upstairs was a dumbass and put nothing around the print

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Paul G. Thompson
The Weenie Man

Posts: 4718
From: Mount Vernon WA USA
Registered: Nov 2000


 - posted 01-07-2001 01:09 AM      Profile for Paul G. Thompson   Email Paul G. Thompson   Send New Private Message       Edit/Delete Post 
It is amazing how many theater owners do not allow an adequate maintenance budget for the booth equipment. That is the worse place, in my opinion, to cut a budget.

Thankfully, the little theater chain I am part of does not cut booth budgets. If I thought I needed booth related items and parts, they want it ordered NOW!!!


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Andy Muirhead
Master Film Handler

Posts: 323
From: Galashiels, Scotland
Registered: Dec 2000


 - posted 01-10-2001 06:10 PM      Profile for Andy Muirhead   Email Andy Muirhead   Send New Private Message       Edit/Delete Post 
Thanks for all your help!

We are now in the process of installing an extraction system for the lamphouse in 4, so will see if that solves our problem.

We happen to be in a special position in that our cinema is run by pro's, not just elevated supermarket managers, so they know that when something is needed in the projection room, they give all the help they can. They know that the booth is the most important room in the place, and not the confectionary counter!

Thanks again,
Andy

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