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» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Humidity and Film-Guard

   
Author Topic: Humidity and Film-Guard
Charles Lubner
Film Handler

Posts: 78
From: Milwaukee, WI USA
Registered: Sep 1999


 - posted 07-11-2000 10:54 PM      Profile for Charles Lubner   Author's Homepage   Email Charles Lubner   Send New Private Message       Edit/Delete Post 
Hey all. I just ordered my first bottle of Film-Guard and I am wondering if it prevents prints from "drooping" in humid conditions. Lately I've been having a lot of problems with film dragging all over the floor because of the high humidity in Wisconsin. Thanks!

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Brad Miller
Administrator

Posts: 17775
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 07-12-2000 12:30 AM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
Drooping??? Could you explain a bit further? What make/model platters?

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Charles Lubner
Film Handler

Posts: 78
From: Milwaukee, WI USA
Registered: Sep 1999


 - posted 07-13-2000 12:37 AM      Profile for Charles Lubner   Author's Homepage   Email Charles Lubner   Send New Private Message       Edit/Delete Post 
I'm using a Strong 5 deck for 2 Pro35 machines. We use 2 ceiling rollers and floor rollers to string the film across when going from platter to projector and back. Because of the humid air the film gets heavy and sags down between the ceiling rollers, onto the floor, getting caught up in the rewind. It's almost as if the payout platter is feeding out the film too fast, but the speed is fine when the weather is nice.

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Brad Miller
Administrator

Posts: 17775
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99


 - posted 07-13-2000 04:14 AM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
That is incredibly common with Strong platters. The ball bearing rollers help it along, making it worse. I've never personally noticed it being worse as the weather changed, but it is an interesting theory as I experienced that problem frequently in Texas (very humid) and Joe said he never had that problem in Colorado (dryer climate).

Generally, you need to place the platters as close as possible to the projector to prevent this. Roughly how far apart is the platter from the projector (film distance in mid-air)? Are these the older style platters with the "on/off" microswitch in the centerfeed, or the newer ones with the leds on the top of the centerfeed?

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John Walsh
Film God

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


 - posted 07-13-2000 09:34 AM      Profile for John Walsh   Email John Walsh   Send New Private Message       Edit/Delete Post 
Nuemade "Nuetronic" platters do this,(drooping) too. You know how the film path through many platters has the film going down to a roller, then up to the top of the mast? On the Nuemade, where the film is going down, it actually overshoots and goes on the floor.

I like that tension thing in the payout heads of Christies.

Maybe a simple fix is to place more ceiling rollers, to support the film more.

There is a fair amount of tension on the film on the take-up side. Yet, you say you have floor rollers to return the film? How far away are the platter/projectors?

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Pat Moore
Master Film Handler

Posts: 363

Registered: Mar 2000


 - posted 07-13-2000 12:01 PM      Profile for Pat Moore   Email Pat Moore   Send New Private Message       Edit/Delete Post 
Hi; I have seen this problem with five-deck installations. Chances are you're somewhere between the two cinemas that the five-deck runs and the film run from platter to the projector is really long. One support roller between the two isn't enough. The humidity apparently makes the film heavy enough in the space between the platter and support roller that it overcomes the resistance of the feed assembly. One thing about the Strong platters, there's almost -0- tension on the feed side and that's why that's happening. Nothing to hold back the film.
If you add support rollers to reduce the span and the resulting film weight the problem will likely go away. You must be right to a point where humidity makes the final difference.


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Joe Redifer
You need a beating today

Posts: 12859
From: Denver, Colorado
Registered: May 99


 - posted 07-13-2000 02:07 PM      Profile for Joe Redifer   Author's Homepage   Email Joe Redifer   Send New Private Message       Edit/Delete Post 
Maybe the top roller on the STRONG platter should be changed so it is not consisted of ball bearings? Just changing that one roller would make a world of difference, and it wouldn't cost too much to do so.

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Pat Moore
Master Film Handler

Posts: 363

Registered: Mar 2000


 - posted 07-13-2000 02:30 PM      Profile for Pat Moore   Email Pat Moore   Send New Private Message       Edit/Delete Post 
Joe;
We have looked at doing that, some change in the top roller or center feed, but everything involves pinching film and we've always tried to stay away from that. Under normal circumstances, where the film is spanning a normal 5-8 feet or so, it's normally not a problem.
Our Wrap Detectors are a little exception to pinching film, though. They keep enough tension on the film so slack is not such a problem.
By the way, you ready to check out that new splicer? It's in the box...


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Joe Redifer
You need a beating today

Posts: 12859
From: Denver, Colorado
Registered: May 99


 - posted 07-14-2000 04:28 AM      Profile for Joe Redifer   Author's Homepage   Email Joe Redifer   Send New Private Message       Edit/Delete Post 
I've been ready. I've been curious as to why I haven't seen it yet. It looks pretty good from what I can tell from the pictures. Is the handle really unbreakable? You do realize that I will have to put it to the test

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Pat Moore
Master Film Handler

Posts: 363

Registered: Mar 2000


 - posted 07-14-2000 06:27 AM      Profile for Pat Moore   Email Pat Moore   Send New Private Message       Edit/Delete Post 
Joe;
I think the splicer might do a better job of parking the car than the Bevin-poos, but as to the handle being really unbreakable... we shall see. We should have it to you soon.

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Joe Redifer
You need a beating today

Posts: 12859
From: Denver, Colorado
Registered: May 99


 - posted 07-14-2000 02:41 PM      Profile for Joe Redifer   Author's Homepage   Email Joe Redifer   Send New Private Message       Edit/Delete Post 
Now you've gone and done it! Now I will have to test the splicer directly against the Bevan-Poos! I don't think I'll put the splicer on the platter to secure the tail, though.

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Gordon McLeod
Film God

Posts: 9532
From: Toronto Ontario Canada
Registered: Jun 99


 - posted 07-14-2000 03:39 PM      Profile for Gordon McLeod   Email Gordon McLeod   Send New Private Message       Edit/Delete Post 
Joe put it on the platter to test the handle that seems how most get brocken anyway being left on the platter

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