Film-Tech Forum ARCHIVE: Weird scratches on film

This is topic Weird scratches on film in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Mike Heenan (Member # 392) on 06-28-2003, 06:15 PM:

Just curious about these scratches on a film, a scan is attached here.

It's on the print throughout a few reels in the same place. I've seen this type of scratch on one other print.

Posted by Paul G. Thompson (Member # 655) on 06-28-2003, 07:51 PM:

More info needed.

What kind of projector are you using?

It is scratches on the base side or emulsion side of the film?

I would guess there was a loop too big, or the intermittant sprocket film stripper is flapping around on the film, or the film is slapping and moving on a stationary part somewhere. It looks like some kind of "flutter scratch" in syncronization with the pull-down cycle. Is your film trap falling apart? and pad rollers ready to fall off?

I never seen these type scratches in real life, but I am sure curious myself.

Posted by John Anastasio (Member # 607) on 06-28-2003, 08:48 PM:

Looks like the kind of emulsion scratch you'll get from running a Christie with the lower loop set too large. The film slaps against the bottom of the Ultramittent on each pulldown.

Posted by Manny Knowles (Member # 1171) on 06-28-2003, 08:59 PM:

Well they should never have released a projector that could do that kind of damage so easily. Are manufacturers in total denial of who's running movies these days?

Posted by Mike Heenan (Member # 392) on 06-28-2003, 09:18 PM:

Hi guys, sorry I wasn't too clear on my post. I did not cause these scratches myself (I run a motiograph AA by the way), its the way it was when it arrived. I thought the cause could be burrs or bumps somewhere along the film path in a projector but I've never seen these types of scratches before except on one reel of another print. And yes the scratches are on the emulsion side of the film.

Posted by Jeff Joseph (Member # 511) on 06-28-2003, 11:00 PM:

I don't think these are scratches.

That's an IB Tech print; check out the sound track.

I've seen this. It only happens to IB. The emulsion "cracks" like this. I think (not positive), that it was caused by the heat of a carbon arc at some point. It tends to be in very dark areas of the print, which would be the place that heat would be absorbed.

I've seen this on several reel 4's of "Ben Hur" (IB prints). Reel 4 is full of dark, night scenes.

Jeff Joseph
SabuCat Productions

Posted by Tim Reed (Member # 137) on 06-28-2003, 11:50 PM:

I've seen this, too. Like Jeff said, only on IB Tech prints. It's like the emulsion wrinkled from being folded or bent or something.

Posted by Paul G. Thompson (Member # 655) on 06-29-2003, 12:39 AM:

Each frame with the same basic pattern? Two prints? I find that hard to believe, but I suppose anything is possible.

I have to side with John, but the damage might have done in a multiple pass situation.

Another thing that could cause it is a very badly worn and hooked intermittant sprocket. Sometimes they won't release the film on pull-down. It'll definately slap the intermittant....depends on how bad the sprocket is worn.

Posted by Darryl Spicer (Member # 711) on 06-29-2003, 12:55 AM:

wouldn't there be emulsion side scratches of the green or yellow veriety if a projector head caused them? What is the name of the movie the scene is from?

Posted by Paul G. Thompson (Member # 655) on 06-29-2003, 01:50 AM:

Darryl, that's why I asked. I didn't see much evidence of what one might expect to see for emulsion scratches. Maybe it was reported in error. Hard telling at this stage....

It could have been caused by an excessively tight loop if it was stock scratch..and that could have caused it to fwap against the heel of the trap between the intermittant sprocket shoe, especially if it was sprung.

Posted by Brad Miller (Member # 2) on 06-29-2003, 04:41 AM:

I would tend to side with Jeff on this. I've been trying to figure out just how that kind of scratch could be made and I keep coming up with nothing close to what I see. Jeff's specialty is things like this and he has an insanely huge film archive and has handled lots of IB prints. I have a feeling he knows what he is talking about here. [Wink]

Posted by Mark Gulbrandsen (Member # 72) on 06-29-2003, 04:47 AM:

Jeff is right,
I have a heat damaged print like this in my collection, It comes ansd goes on my print on only one reel. And I've only seen it happen to I.B. Tech. Some of those 80 foot wide indoor screens with lamps that are just too large for the film format......
Mark

Posted by Paul G. Thompson (Member # 655) on 06-29-2003, 12:32 PM:

[Smile]

Posted by John T. Moon II (Member # 1694) on 06-29-2003, 07:45 PM:

This damage looks similar to what I saw when our cooling pump quit working on our 5k lamphouse. After a few passes this is similar to the damage we saw on the print which was our flag to a real problem with our system.

Posted by Randy Stankey (Member # 64) on 06-29-2003, 10:59 PM:

This may be way the hell off base but what the hell...

I've seen some scratches of similar nature occur when somebody cleans the intermittent sprocket with a toothbrush while the motor is running. One of the bristles gets caught in the sprocket and is pulled right out of the brush handle. The resulting "hair" in the sprocket flaps against the film.

The damage will be on the emulsion side and will build up into a fan shaped pattern as more and more runs are put on the print.

Posted by Stan Gunn (Member # 554) on 06-30-2003, 01:25 AM:

I've seen this sort of pattern on film that was held to tight between the fingers while hand winding,

causing the film to take on a v shape between the fingers. [Frown]

Posted by John Anastasio (Member # 607) on 06-30-2003, 05:10 AM:

The more I look at the pictures, the more I'm convinced that Jeff's answer is the right one. Scratches would be the same on each frame. These look more like cracks and the pattern is random. The sudden expansion/contraction caused by a high intensity arc makes sense to me. And like you say....Jeff's our "stock" expert.

Posted by John Pytlak (Member # 331) on 07-02-2003, 10:29 AM:

I agree that they have the appearance of some sort of stress cracking, perhaps caused by severely pinching the film while it was too dry and brittle. From the photo, it does not look like a "hot spot" heat damage, which is usually isolated to the darkest areas of the image that absorb the radiant energy during projection.

How old is the print?

Unlike incorporated coupler films, dye transfer prints do not have separate emulsion layers for each dye, so emulsion-side scratches do NOT show the usual progression of black->green->yellow->white scratches with increasing severity of the scratch.

Posted by Leo Enticknap (Member # 534) on 07-03-2003, 01:58 AM:

quote:
Scratches would be the same on each frame. These look more like cracks and the pattern is random.

They're not indentical on each frame, but they don't look totally random to me either - similar, but not identical. The scratch patterns seem to stem from the bottom of each frame and branch out toward the top.

The similarity would suggest to me that the primary cause of the emulsion cracking took place when each frame was stationary in the gate - entirely consistent with heat damage as suggested by Jeff.

Could it possibly be that base shrinkage on quite an old element (I notice film curl toward the top left of the picture) had stressed the gelatine and/or dye layers, making the emulsion quite fragile to start with, and then the extra stress caused by the lamp heat finally pushed it over the edge and inflicted those cracks?