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Author
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Topic: Cleaning 35mm films from scratches
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Leo Enticknap
Film God
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Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000
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posted 02-22-2017 10:02 AM
Scratches cannot be "cleaned" in the sense of removed completely. If what you are trying to do is to scan 35mm still images in such a way as to render scratches invisible, then basically you have three non-digital options.
1 - Rewash the film in order to swell the emulsion enough to "heal" light emulsion scratches. If you put the processed roll into a developing tank and then immerse it in distilled water, agitating it gently every now and again for a few minutes, and then hang it up to dry, you may find that this helps them a little.
2. Professional film restoration labs can address scratches on the base side of nitrate and acetate film by polishing it on a rotating, polished glass wheel (this doesn't work for polyester, because it's too thin and too tough). I know of no commercially available setup for doing this to consumer, stills 35mm, though.
3. Use a non-volatile, wet cleaner such as Filmguard (easily the best of all the options of this type on the market, IMHO) to fill in the scratches. The liquid has an almost identical refractive index to the film base itself, thereby reducing the visibility of the scratch in scanning or projection. What you're doing with this is essentially a cheaper and easier way of achieving the same result as wet gate printing.
If 3 is not an option for you because it may cause damage or malfunction to the scanner, then the best option I can see is to Photoshop the scratches out of each frame after scanning. It's time consuming and involves a learning curve, though.
The only dry coat scratch filler I know of is 3M Photogard (formerly known as Scotchgard), but it shrinks and goes yellow and brittle over time. Professional film restorers have had nightmares in situations where a Scotchgarded element is the only surviving one.
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Sergio Ocampo
Film Handler
Posts: 4
From: La Unión, Chile
Registered: Feb 2017
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posted 02-22-2017 12:47 PM
Hi Leo, thanks for this useful information. It seems option 1 is my best chance: Option 2 won't help me because almost all of the films I have are polyester. Photoshop is very useful and I've removed scratches before but this time I have 420.000+ negatives to scan so it will take literally forever. Option 1 is still tedious but I think it's more doable than the others. FilmGuard is a great option but it will only work if the liquid has a similar consistency as vaseline. When I tried the liquid vaseline, the results were pretty good and the scanner did not make a mess with it. I applied the vaseline in both the emulsion and the base. Then, I rubbed the vaseline out gently with a piece of cloth so the vaseline is kept only where it was meant to be (the scratches) and not in the rest of the film. So, I'm thinking the FilmGuard would work very well if the liquid is not so-liquid and more vaseline-like, if that makes sense.
Also, it just occurred to me that, considering the vaseline worked out that well for me, I can use it just to scan, but then the film can be cleaned with a special liquid (I'm pretty sure it exists, if you know the name or any other liquid that does this please let me know) that will dissolve all the vaseline out of the film and returning it back to normal for when I archive them.
So, summarizing: Do you know if the FilmGuard consistency is similar to vaseline? I think not because for what I know, the FilmGuard dries out all by itself and in a short period of time, so I think it has to be a fairly light liquid to be able to do that. But you never know with science. Also, what do you think about using vaseline and then cleaning it?
Thank you very much for your time. I hope I made sense.
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