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Author
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Topic: Scratch question
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Ben Goodman
Film Handler
Posts: 32
From: Danbury, CT
Registered: Apr 2008
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posted 05-18-2008 03:43 AM
There's a scratch that I have not been able to figure out the cause of and there's no place better to ask than here... I want to figure out if this is operator error, equipment malfunction, or both.
The projector in question has a DTS caption penthouse reader, a Cat701 dolby penthouse reader, and the rest is standard Strong Millenium-- it looks identical to the one Joe reviewed on this site. Platters are Christie AW3Rs.
The print in question has standard AMC preshow, 6 trailers, then the 6 reels of the movie. What is also interesting is that the scratch does not run throughout the entire movie-- the trailers are perfectly fine to the point that even on the static green band, nothing is visible. In the first reel, multiple vertical black lines appear on screen but they're thin and seem relatively constant in terms of magnitude. As the film continues, the scratches get deeper, wider, and start to weave back and forth-- some get really awful. It looks like long sine waves from the top of the screen to the bottom. At the beginning I'd say 3-5 black lines are visible, but towards the end it looks like there are upwards of 10 different marks.
What would cause a scratch like that? The requirements are...
1. Multiple points of contact
2. Constant contact
3. Weave back and forth across the points of contact
I don't know what would cause it to get worse as the print kept playing either. We had a couple theories, but neither of them seemed to fit... if it slipped off a roller and hit a platter, that would explain the weaving but the lines would probably be diagonal. If the top loop was too small and popped the lock, it's possible that the print was rubbing against the top of the film gate-- but I'm not sure if that would create that sort of scratch and sprocket damage would probably occur from the film bouncing against the teeth of the unlocked sprocket at the top.
Any ideas? I can try to get pictures as well.
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Brad Miller
Administrator
Posts: 17775
From: Plano, TX (36.2 miles NW of Rockwall)
Registered: May 99
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posted 05-18-2008 03:58 PM
If the print was used, then that's pretty easy to figure out what happened. However I'll bet he didn't bring this to us because he got a used print.
ASSUMING the print was new, I am pretty sure I know what happened, but I must ask how he builds films to pinpoint exactly.
*If the print was built entirely on a rewind bench using a Goldberg platter reel, then you did not scratch the print during makeup. It is virtually impossible to do when using this valuable tool anyway.
*If the print was built using two 6000' reels, I have to ask if the trailers were attached to reel 1-2-3 or loaded on it's own reel, and THEN the movie was built on it's own via 6000' reels.
*If the print was built using 2000' shipper reels entirely on the makeup table...you guys suck.
Putting the suckage part aside, my guess is that the trailers were loaded on it's own reel via the makeup table to the platter and permitted to "tail out". THEN the movie was loaded onto the platter either via 6000' reels or the sucky way of loading directly from the 2000' shipping reels. When the splice was made and the film re-situated on the lower roller of the makeup table, the film was wrapped AROUND the metal keeper bar, not in between the bar and the roller. It is a common mistake and why I always make it a point to go in and reposition that metal keeper arm so that it is sitting at the 4:00 position (so it is easily seen.)
One other note, because the scratches get deeper and more awful, that coincides with the fact that the tension gets greater as the diameter of film on the makeup table diminishes. So if he loaded via shippers, he will see the beginning of each reel less damaged than the end. If he loaded via 6000' reels, then he will see reel 1 nowhere near as bad as reel 3, then at the beginning of reel 4 the scratches will immediately tame themselves and during the rest of that reel 4-6 the scratches will get as bad as they were by the end of reel 3. (This assumes reels 1-3 were built to the first 6000' reel and reels 4-6 were built to a second 6000' reel.)
Now go get your wrench out and reposition that metal keeper bar on the makeup table so this doesn't happen again!!!
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Ben Goodman
Film Handler
Posts: 32
From: Danbury, CT
Registered: Apr 2008
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posted 05-18-2008 09:51 PM
Well, Brad's exposition was very thorough, but unfortunately because I misjudged the nature of the scratch and did not provide enough information, we get to start this game of problem solving over. Though thank you folks for the explanations you've already given and I apologize for taking the initial information for granted.
So, I will provide all information I have about print buildup and the timing of the scratch etc.
For starters, I grossly miscalculated the nature of the scratch because I only saw the very end of the print and what I thought was an undulating scratch was really just a couple different scratches on top of each other-- however this was only in the blue part at the end of the print itself, so it's not really a major concern considering most houses cut it off. In reality, there are four or five different vertical black lines that look like roller scratches. They're spaced out relatively well between the print, but one in particular is just to the right of the center of the screen and it shakes back and forth, further leading me to believe that it was a misthreaded roller. However, again, the trailers are not scratched.
As for the makeup of the print, it was a new print and we build/load our prints onto 6ks from our RTV-8900 rewind tables. The trailers and the first two or three reels go onto one 6k and the rest goes on to another (unless it's a 9-reel monster like Narnia). The print is two weeks old, so it was not scratched during loading. It happened at some point between Thursday at 5 pm and Friday at 7 pm, and what I'm really trying to pinpoint is if this is one set of scratches or two.
I do not believe that there is a single roller on either the AW3s or in the projector itself that could cause all of those straight black vertical lines. It could very well be multiple roller misthreads on the same show, but at the same time, I would be inclined to believe that it would scratch the trailers as well. What would cause the scratch into the print itself?
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