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Advice For Cleaning Damaged Film Stems

Published : 15th June 2013

I have some 16 and 35mm negative stems I need to scan. The film is pretty beat up and has moisture damage. The problem this presents is literally thousands of white spots on the resulting scan. The moisture allowed dirt and debris to penetrate into the soft emulsion layer.

Before I touch the film what would be the best way to approach this? The clips are maybe 10 frames long. I was going to try Kodak's film cleaner but I'm afraid the rewetting will loosen the dirt and cause even more scratching damage to the emulsion layer. The base is relatively clean.

Perhaps a dirt removal software plug-in for CS2 might be a better way?

The built in CS2 dirt-scratch removal plug-in can't handle it without removing major amounts of detail with it.

Tom McDonnell, SOC
IATSE 600
New Orleans, La


Tom,

You could possibly rewash the film. If you do you will lose at least a frame on either end of your select clips because of splices that have to be made to re-develop the negative. Is it all colour negative stock?

Vincent G. Hogan
President
Cineworks Digital Studios, Inc.
Miami


Hello Tom And Vinny-

What is a "film stem"? Is it a short length of processed frames?

If it will fit onto a flatbed scanner, maybe you could just soak it in warm distilled water for a minute or two, and then lay it right on the scanner bed emulsion down (WET) - wipe off any excess water on top with a clean, dry, lint-free paper towel and scan away.

I used to do much photo-restoration in the good 'ol analogue organic days, as general manager with a very small neighbourhood photo lab. (If you ever rode the JUNGLE QUEEN dinner boat between Dec. 1979 and July 1986, the odds are that myself or one of my crew took your picture!).

Sometimes a mould grows on old, humidity-stored negs...water seems to render them transparent while they are wet.

What do you think, Vinnie? Worth a try before the PHOTO-FLO*(*ANOTHER MEMBER OF THE KODAK FAMILY OF FINE QUALITY PRODUCTS) bath??? Did those 4 H/S cores get FedEx'd to Burbank for me ??????


Bill Gula
USA


Tom McDonnell wrote:

>> The film is pretty beat up and has moisture damage.

There are a lot of different ways in which an emulsion can get beat up so the object of cleaning is to fix each one without introducing further problems. (I'm not sure how much of this can be a do-it-yourself at home kind of issue).

>> I was going to try Kodak's film cleaner but I'm afraid the rewetting will loosen the dirt

Assuming the emulsion hasn't separated from the base then the first thing you should try is a professional film cleaning machine typically using perc or naptha. The solvents will take out a lot of surface contaminants (and is very similar to dry-cleaning). Use of an aqueous cleaner should be avoided when the
original damage was water based. Handling pro film cleaners is hazardous so take the recommended precautions.

If the emulsion is sound and has some large debris embedded on the top layer, you can run the film through PTR rollers – particle transfer rollers. This isn't recommended if there are a lot of pinholes down to the base of the emulsion or curls at the edges that appear to be separating from the base.

If there are a lot of surface scratches to the emulsion, it is worth the trouble to find the rare custom-built wet-gate digital scanners. Failing that, you might get the negative copied on a wet gate printer to make a new internegative. Then scan that. (You'll lose a generation here so it is a trade-off of how much damage versus how much detail exists.)

Assuming you have the best possible scan you can make (a 4K scan will give you a lot more to work with for a restoration),

>> Perhaps a dirt removal software plug-in for CS2

You might want to look for some dirt removal software that does motion based analysis and restoration. This will give better results than Photoshop’s filter. For moving images, Photoshop doesn't replace the artifacts but just knocks their luminance down to the average of the surrounding pixels. This causes some weird subtle popping when in motion. Sorry I can't name the best package for this off the top of my head...

Jim Houston
Starwatcher Digital


>>For moving images, Photoshop doesn't replace the artifacts

Agreed, though in After Effects, one can easily clone the same spot from adjacent frames, which might be more help. Your trims are very short, though.

Tim Sassoon
SFD vfx & creative post
Santa Monica, CA



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