Film-Tech Forum ARCHIVE: Vertical center scratches

This is topic Vertical center scratches in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Dan Chilton (Member # 2288) on 12-31-2008, 06:56 PM:

What might cause a collection of multiple, small, vertical scratches to appear right down the center of the frame? Could they be stress scratches from the film being too tight somewhere along the path?

Posted by Tim Reed (Member # 137) on 12-31-2008, 11:13 PM:

Possibly. It could also be a protruding screw on something like the intermittent pad shoe assembly. I've seen people replace lost screws with ones that are slightly longer. In once instance, I had a theatre with TWO houses running gates that had pad shoe screws extending noticeably (by as much as 1/4" or more) into the film area, damned near slicing the film in half, and they wondered why they were scratching prints. [Roll Eyes]

Look to see which side of the print the scratches are being made. Definite green or white scratches would be on the emulsion side; black scratches are most likely on the base side. This will direct you where to look in the film path, as you narrow down the possibilities.

Posted by Jeremiah Teague (Member # 5052) on 01-11-2009, 04:40 AM:

I've had a screw on the trap of a film gate loosen it's way out and cause a scratch like this. It got really bad before I figured it out. 1st run through --> black scratch, 2nd --> green, 3rd --> white. I'm still pissed it took me that long to figure it out. I just never thought to look there.

Posted by Gordon McLeod (Member # 33) on 01-11-2009, 11:20 AM:

You don't tell us what projector is involved
Often too large of upper loop on a vic5 will hit the apperture plate changer linkage putting short vertical marks in the centre

Posted by Ron Funderburg (Member # 4561) on 01-12-2009, 06:29 PM:

It could be caused by the drum on the sound head. If the drum doesn't turn easily the film drags across the drum causing black scratches to the non emulsion side. The culprit in this instance is the barrings.