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Author Topic: Strange Black "Snow" on One Side of the Frame
Patrick Matthews
Film Handler

Posts: 86
From: Kansas City, MO, USA
Registered: Sep 2004


 - posted 09-09-2005 01:44 PM      Profile for Patrick Matthews   Email Patrick Matthews   Send New Private Message       Edit/Delete Post 
I just recieved a print of March of the Penguins and I just previewed it and saw something odd. On the right hand side of the screen there are little black dots that look almost like "snow" that you would see on a TV that is not recieving a signal from a station. This goes from the top to the bottom of the frame and is only on the right hand side of the image. I noticed during build up that the print had quite a bit of oil on it and I have never seen this on any print that I have played. What might be the cause of this? Thanks!

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Dan Lyons
Jedi Master Film Handler

Posts: 698
From: Seal Beach, CA
Registered: Sep 2002


 - posted 09-09-2005 02:13 PM      Profile for Dan Lyons   Email Dan Lyons   Send New Private Message       Edit/Delete Post 
Maybe a bad pad roller did the damage (tick marks from a burr)? Dirt buildup?

You need to get a new print right away. That film is entirely sky and snow, if you have anything less than a pristine print it will look like hell and everyone in the audience will notice the dirt and damage. [Eek!]

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Patrick Matthews
Film Handler

Posts: 86
From: Kansas City, MO, USA
Registered: Sep 2004


 - posted 09-09-2005 02:15 PM      Profile for Patrick Matthews   Email Patrick Matthews   Send New Private Message       Edit/Delete Post 
I know of the "tick" scratches that you refer to, we had that problem here a few months ago, and that is now what i'm refering to. It's hard to explain but they are smaller than tick scratches would be.

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Olivia Coleman
Film Handler

Posts: 53
From: Bend, OR USA
Registered: Jun 2005


 - posted 09-09-2005 03:30 PM      Profile for Olivia Coleman   Author's Homepage   Email Olivia Coleman   Send New Private Message       Edit/Delete Post 
We get this problem from time to time from prints shedding and if someone doesn't clean it fast enough the film dust will cook onto the print. This is usually seen on the right side, I think, due to how it ends up sitting on a platter which would be soundtrack up... I'm thinking gravity gets to the better of the dust and it sits more on one side than the other... But that's just a theory!

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Brad Miller
Administrator

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


 - posted 09-09-2005 03:45 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
Projectors with a Simplex or RCA type soundhead that have the pressure roller are commonly guilty of this damage.

Clean the print immediately, and I don't just mean one pass or with PTRs. It may be too late.

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Monte L Fullmer
Film God

Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004


 - posted 09-09-2005 03:56 PM      Profile for Monte L Fullmer   Email Monte L Fullmer   Send New Private Message       Edit/Delete Post 
Look at your pad roller assembly that covers the middle constant speed sprocket - the sprocket that is right after the intermittent (mainly for the Simplex, but other domestic makes as well) assembly that gathers the lower loop of film.

Look at that front (left) roller - the roller that is at the head of the pad arm assembly and the roller that the film touches first. If the front roller has what's called "shoulders" - it's a smaller diametered inner flange that the sprocket teeth passes through between this inner flange and the outer flange of the roller.

What happens is that, if the bottom loop is built too big and I've seen it happen with almost normal sized loops, the film rubs against this inner flange causing these linear scratches, on the base side of the film, to appear.

Order some non-inner flanged ("shouldered") rollers and replace the shouldered ones with these rollers. This will eliminate this linear scratching.

Also, adjust the pad arm assembly to where, with two layers of film over the sprocket, both rollers should still turn freely. If the assembly is closing too tight, this is major cause of linear scratching, since the rollers aren't turning freely, plus major wear on the rollers.

thx-Monte

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Gordon McLeod
Film God

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


 - posted 09-09-2005 04:30 PM      Profile for Gordon McLeod   Email Gordon McLeod   Send New Private Message       Edit/Delete Post 
Brad said "Projectors with a Simplex or RCA type soundhead that have the pressure roller are commonly guilty of this damage"
They have contact only in the center area so the damage would be there not off to the side?

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Brad Miller
Administrator

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


 - posted 09-09-2005 04:54 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
You would think so Gordon, but I've found that the pressure roller will embed dirt into the center of the film (from the left edge of the image over most of the way to the right) and cause a buildup of dirt on either side of the roller (meaning the projected right edge of the image and all over the optical soundtrack). If cleaned immediately, sometimes that dirt on the soundtrack and right edge can be removed. If projected too many times before cleaning, it's permanent.

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Patrick Matthews
Film Handler

Posts: 86
From: Kansas City, MO, USA
Registered: Sep 2004


 - posted 09-09-2005 05:15 PM      Profile for Patrick Matthews   Email Patrick Matthews   Send New Private Message       Edit/Delete Post 
Monte - These are not vertical scratches but tiny little dots.

I'm having a hard time communicating what exactly it looks like, I think. Further examination showed that I needed to get pretty close to the screen to see it and there is no pattern to it. I'm assuming that this happened at the previous theatre it was at as it has never happened in one of our projectors (that is not to say it COULN'T happen). I will clean the print ASAP

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Brad Miller
Administrator

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


 - posted 09-09-2005 05:17 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
If the screen was 20 feet wide (you tell us whether you are flat or scope), how far into the image from the right masking do the marks project? That will at least give us an idea.

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Patrick Matthews
Film Handler

Posts: 86
From: Kansas City, MO, USA
Registered: Sep 2004


 - posted 09-09-2005 05:28 PM      Profile for Patrick Matthews   Email Patrick Matthews   Send New Private Message       Edit/Delete Post 
It is 42 feet scope and this film is flat and I would say that it goes in from the right side of the masing 1 foot to 1 and 1/2 feet.

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Brad Miller
Administrator

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


 - posted 09-09-2005 06:56 PM      Profile for Brad Miller   Author's Homepage   Email Brad Miller       Edit/Delete Post 
Assuming you aren't overly cropping the image, that sounds like pad roller scuffing as Monte detailed above.

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John Pytlak
Film God

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


 - posted 09-09-2005 09:04 PM      Profile for John Pytlak   Author's Homepage   Email John Pytlak   Send New Private Message       Edit/Delete Post 
I agree with Brad and Monte --- likely pad rollers are scuffing the film. Slight roughness or burrs will lightly abrade the film surface, which over a period of time will become visible.

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Gordon McLeod
Film God

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


 - posted 09-09-2005 09:59 PM      Profile for Gordon McLeod   Email Gordon McLeod   Send New Private Message       Edit/Delete Post 
I have seen some DTS readers also cause a edge scuff as well

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