This is topic Haphazard Scratches in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.


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Posted by Thomas Procyk (Member # 1170) on 01-03-2003, 02:20 AM:
 
I've noticed a strange anomaly (anomalie?) on our print of Lord Of The Rings. Occasionally, a scratch will pop up, then go away that was never there before. It doesn't happen at any specific time, like at a splice or anything, and disappears before I can call my manager to come see it.

These are all very thin, hairline base scratches. One is somewhat thick, and appears in a dark scene on the far left in Reel 5, then too goes completely away never to be seen again. The hairline scratches also appear for a brief moment (1-4 seconds) and then go away. There are 3 or 4 I have noticed on the print in different places on different reels.

It can't be that the entire print is scratched and that it's sometimes more apparent in different places. There are scenes in the film where the screen is completely white for several seconds, and there aren't any imperfections whatsoever. Examination of the film itself also showed no signs of scratches in other parts.

I noticed the scratches about 4 days after a second application of FilmGuard as per our rotating film cleaner schedule, so the possibility of dirt causing the scratches is minimal. (or is it?) Rollers were all lubricated and spin freely, so nothing could be getting stuck for a brief moment to cause it. The projector is clean and doesn't have anything strange sticking out to cause it, either. There's a DTS unit in this house, but everything spins well on that, as well. Everything was fine until I got a few days off and came back to notice the scratches.

I want to know if anyone has any idea as to what could be causing these random little scratches everywhere. Dirt getting caught in the aperture and then springing loose? Operator error? (if so, what error? Everything I could think of would cause constant, uniform scratches) Ghosts? Hobbits??

Any information would be appreciated.
=TMP=
 

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Posted by Brad Miller (Member # 2) on 01-03-2003, 03:10 AM:
 
We need equipment lists.

(I screened a print of About Schmidt this evening that was brand new from the lab and it had scratches such as this randomly through it. I kept thinking there was a stain on the screen or something, but a few seconds later it would not be there. Since the projector did not have any shedding when the movie was over and no form of film cleaner was used for this one time run, it had to have come from the lab that way as there was nothing in the chain that could have possibly caused those marks.)

Before I forget, has this print "moved down" to a smaller house? I generally find that most of the smaller auditoriums in complexes are much brighter than the big houses. Because of this, many scratches are not visible on the big auditorium, but become very obvious on a smaller screen that is brighter.
 

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Posted by John Pytlak (Member # 331) on 01-03-2003, 08:43 AM:
 
Random base-side scratches on a new print could have occured during the processing of the print. Most processing machines run with the base side towards the rollers, and variations in machine tension can make the film pull in and touch a machine component:

http://www.kodak.com/US/en/motion/support/processing/h249/h2409_02.shtml

http://www.screensound.gov.au/glossary.nsf/Pages/Processor?OpenDocument

Random base cinches can also occur in the projection room, if the roll is slightly loose and the film laps slip past each other during winding or handling.

Kodak VISION Color Print Film has a scratch-resistant anti-static backing that offers superior qualities not found on other print stocks (e.g., it doesn't scratch as easily):

http://www.kodak.com/US/en/motion/products/lab/2383.shtml

http://www.kodak.com/US/en/motion/products/lab/2393.shtml

Interesting that these scratch incidents are both on prints that were NOT made on Kodak film.
 

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Posted by Darryl Spicer (Member # 711) on 01-03-2003, 09:22 AM:
 
one thing to look for is the sound drum. Make sure that it is turning freely and does not present the early signs of the bearings going out.
 

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Posted by John Pytlak (Member # 331) on 01-03-2003, 12:14 PM:
 
Darryl wrote: "one thing to look for is the sound drum. Make sure that it is turning freely and does not present the early signs of the bearings going out."

Thank you. I forgot that one. Even if the sound drum is turning freely, be sure there are no burrs or pitting that could scratch the print. Even if it turns freely, there is some slippage between the print and the drum, especially while running up from stopped to sound speed.
 

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Posted by Michael Gonzalez (Member # 593) on 01-03-2003, 12:18 PM:
 
I have a good one. What would cause 15 to 20 vertical black scratches to appear on the print during one run of the film (scratches top to bottom across the entire print)? Meaning one run the picture is perfect then the next time it is run the scratches are there. I had this happen two years ago and just recently two months ago. Both time the shows were run by a relatively new booth operator (something like two or three weeks experience). To this day I have not been able to figure out just how the film was misthread to cause that amount of scratches to appear at one time. We are running Christie projectors and Potts platters.
 

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Posted by John Pytlak (Member # 331) on 01-03-2003, 12:31 PM:
 
Michael wrote: "I have a good one. What would cause 15 to 20 vertical black scratches to appear on the print during one run of the film (scratches top to bottom across the entire print)?"

That's NOT a "good one" --- it's really BAD.

A misthread is the most likely cause. The film was running flat against an abrading / non-rotating surface that caused vertical abrasions across the entire film surface. For example, skipping a guide roller can sometimes have the film rub against the metal casting of the projector. Another possibility is running the print through a dry media cleaner that had become loaded with abrasive dirt or had a defective media transport.
 

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Posted by Thomas Procyk (Member # 1170) on 01-03-2003, 12:56 PM:
 
Here's a copy from an e-mail I replied to Brad:

Century (SA?) Projector, Strong Alpha platters (older models where the control plate/brain doesn't come out), Christie film cleaner, Media is whatever brand the theater has. They're white and outlast a 3 hour movie. I'm guessing Kelmar? Media is changed every 3-5 runs, unless they come off really dirty. Each time the film cleaner was run on Lord Of The Rings, it was new pads though. Print has been running 4 shows a day since December 18th, now down to 3 shows on the weekdays as of Jan 1, 4 on the weekends.

Also note that the print has not moved from this house since it began its run. These scratches also appeared recently, so it couldn't be that way from the lab.

The sound drum!! That hasn't crossed my mind but is a possibility. How can you tell if the bearings are beginning to go bad, if it still spins freely?

Thanks,
=TMP=
 

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Posted by Brad Miller (Member # 2) on 01-03-2003, 04:14 PM:
 
Michael, I'll bet anything that that first run was misthreaded somewhere past the picture aperture, so the damage was not seen on-screen until the next showing.

Thomas, Big Sky and FT media is clearly labeled on the box. That leaves either Neumade or Kelmar. So long as the media was turning, especially since you say the media was changed every run, I highly doubt this is a cleaner issue though.

I have seen the film get "sucked" up against the side of a platter tree during payout from static which can produce those scratches intermittently. Other things you could look for would be that perhaps the film was misthreaded on the wrong side of the input guide roller as the film inputs the projector head. Century projectors have as you know a very small opening there and could cause that. Have you checked the platter itself? If you have one deck that is wrapping a full round such that the film is rubbing against itself on payout, that can also cause those kind of intermittent scratches.

Pretty much what you need to do is first thing closely examine a stretch of film where the scratch is visible on screen and make sure it really is on the base side of the film, since light emulsion side scratches are black too. Then start watching the equipment as well as your projectionists. See who threads which way. In the end it will probably end up being from a one-time misthread.
 

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Posted by Joe Redifer (Member # 3) on 01-03-2003, 08:16 PM:
 
Michael & Thomas, create about 10 minutes or more of junk trailers that are not scratched if you can. Misthread in every possible way until you get the identical scratch. I had to do this once to prove I wasn't the one who scratched a print when I was being blamed for it.

As for Michaels' scenario, perhaps the individual threaded over BOTH rollers at the top of the Strong platter tree while taking up on the center or bottom deck?
 

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Posted by Mathew Molloy (Member # 666) on 01-04-2003, 05:34 PM:
 
I need a little help figuring this one out... I'm getting occasional emulsion scratches exactly one frame past a splice. They're showing up just to the right of mid-frame and about a quarter of the frame tall. I'm running a Norelco AAII and Christie AW3. No one's having problems with loop sizes as I've taught them to be very particular about that. I was thinking it might be the splicer, but I've checked it out and I don't think so. I'm stumped.

(On a side note, when we took the theatare over last year the rollers below the intermittent were so worn down that the film was rubbing against the mechanism that locks the film against the intermittent! I replaced those immediately.)
 

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Posted by Brad Miller (Member # 2) on 01-04-2003, 06:29 PM:
 
Oh that one's easy Mathew. You said you are running an AAII and an AW3 platter. Why there you have it. The platter is ALWAYS at fault!

Actually I would recommend you go over the splicer again. In every instance I have seen something like that "just pass the splice" it has always been the splicer. Try punching a fresh splice about 30 times, flip over and repeat. Now closely examine and see if there is a mark. Only then would I start to look at the projection equipment. (However since it only happens right after splices, you can bet it's in the projector.)
 

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Posted by Gordon McLeod (Member # 33) on 01-04-2003, 06:56 PM:
 
Must be a Neumade Splicer
 

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Posted by Mathew Molloy (Member # 666) on 01-04-2003, 11:03 PM:
 
It's a Strong splicer only 9 months old, never been dropped, banged, dinged, stapled, folded or manipulated. I'm pretty sure it's not the splicer though. I mean, why would it cause a 1/4" long vertical scratch just past the splice? Besides, the scratches aren't there until many runs later (I think...). It's tough having to notice every nuance of the booth and presentation when I have to manage the theatre as well!

On a side note, it's a great lil' splicer except for the fact it punches holes larger then the actual sprocket holes. (Forget using this on 4trak mag) but I AM getting excellent splices with no jump in the gate.
 

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Posted by Gordon McLeod (Member # 33) on 01-04-2003, 11:20 PM:
 
Holes larger than the perf condemns it to splicer hell
Does it actually incurr into the DD data area and the soundtrack guard band
 

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Posted by Mathew Molloy (Member # 666) on 01-05-2003, 01:52 AM:
 
Hey Gordon, I'm really glad you asked because I never took a real close look before. Looks like it barely cuts off the black border around the SRD info and takes a little chunk out of the lower corner - also invading the soundtrack area (probably just enough to be noticed when running analog). It also barely invades the SDDS info. too. That being said we've run all SRD since we got this splicer in March and havn't had any dropouts as far as I can tell.

I'll see if I can't scan it and post a pic.

Kinda sucks as the splicer is solid as a rock and it takes no force to punch the splice. (Is that the correct term?). Brad, this is the same model splicer you gave an A- in the Reviews section. Did the one you review have the too-large-a-hole problem?

Gotta say that a couple months ago the assistant editor of XXX was in here for a Premiere screening and she built the print up herself using single sided 8-perf. It was real nice - no jumps in the gate and not a sound of the splice going through. She had never built up on a platter before but she caught on pretty quick.

EDIT-

Brad, I just tried what you suggested and made a dozen splices and you know what? OPERATOR ERROR CAUSES THE SCRATCH! I realized that when prior to cutting the film I sometimes inadvertantly slide the emulsion side along the surface edge next to the blade as I align the frame line. (Make sense?) How long have I been doing this? Hmmm, never noticed though before this splicer - probably because it's new and those edges are sharper? THANKS FOR THE TIP!
 

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Posted by Thomas Procyk (Member # 1170) on 01-06-2003, 11:06 AM:
 

quote:

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one thing to look for is the sound drum. Make sure that it is turning freely and does not present the early signs of the bearings going out.

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