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02-06-2017, 09:46 AM   #1
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If your expired color film has a color shift, can you compensate with a lens filter?

This is a question about shooting photographs, NOT processing.

Has anyone with some quantity of a certain brand and speed of color print film, after shooting a roll and discovering a PARTICULAR kind of color shift in the scans or prints, tried shooting the next roll with some kind of correction filter on the lens? And if you did, did the filter help?

This obviously raises the question of whether color shift in film, due to age, means that the colors are merely out of balance OR whether certain colors simply can't be reproduced well at all in the film anymore. If the answer is the former, then it would seem that the color shift might be corrected, or partly corrected, with lens filters.

If different color films experience different kinds of color shifts, then it might mean shooting a roll without filters would be necessary for each lot of a particular kind of expired film. before one could estimate what kind of correction filter might be helpful. If you only had 3 rolls of a particular aged film, then you'd blow one on the test (unless it turned out okay), in order to improve the other two.

Anyway, has anybody tried this? Did it work at all in your experiments. If you posted about it previously, please link the earlier thread. I searched but didn't find anything on this subject.

02-06-2017, 10:54 AM   #2
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Tricky! It depends on what's causing the color shift.

If the color shift in the film can be corrected simply by changing the white balance (which is equivalent to a linear shift in the ISO sensitivity of one or more color layers), then a color filter (and derating of the film ISO value) would help.

If the shift is more complex (e.g., fogging of one color, bleaching of the filtration layers, spectral shifts in the couplers, etc.), then a color filter might not help as much.

Yet if one took a set of maybe 3 to 7 test shots with a colorchecker target at various levels of under and over exposure, then analysis of those results could create the right mathematical function for mapping the values in the negative back to the right values in RGB.
02-06-2017, 11:18 AM   #3
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If it were in the realm of complex possibilities you describe, photoptimist, a lens filter might not help much; however, if one had 10-20 rolls (or more) of the same stuff it might be worth trying.

On the other hand, if the prints or scans of the first roll just came out a just a little bluish, I wonder whether a mild warming filter might make the next roll more pleasing...maybe even just using a Skylight 1B would make a difference. Or maybe it would take an 85B....unless the cause of the blue was lost in those complex interdependencies.

If fogging tends to be caused by gamma rays, as I have read, even when old film has been refrigerated since an unexpired purchase date, I wouldn't expect a lens filter to help a lot with that.... If the fogging is mild, doing something like shooting at a somewhat lower iso might hide some of it I suppose.
02-06-2017, 01:52 PM   #4
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The simple answer is no; you cannot fix the color balance on expired film by using a color correction filter mainly because all filters subtract color and do not add color that is gone or needs to be restored.

This is an oversimplified explanation, but essentially color film is three monochromatic sensitive layers of cyan, magenta, and yellow. They do not all fade at the same rate, but letʻs just say cyan fades the fastest. The remaining magenta & yellow layers will give a red looking image because cyan is missing. If you put a cyan filter on the lens, that would logically balance the red image, but in reality, the cyan filter will block magenta and yellow light. It wonʻt add cyan to film that canʻt record cyan any longer.

This next example is a bit of apples and oranges, but the same concept applies: Have you ever shot in tungsten lighting with daylight film and a blue tungsten correction filter? Or in daylight with tungsten film using an orange daylight correction filter? The color balance is better, but you wonʻt get a full color spectrum because the filter is eliminating specific wavelengths from the emulsion.

At best, I would shoot without any color correction filters and then use digital "filters" in post processing to restore/add the missing colors. I use quotes with the word filter + digital because by definition, a filter blocks and subtracts certain elements from passing. In the digital sense, filters are often used to add. I guess we still use the term filters in the digital usage just like people say they "film" a scene when there is no film, or that you dodge an image, when there is no actual blocking of light to lighten the print, but it is done in the abstract sense with the same affect with pixels.

02-06-2017, 09:32 PM   #5
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My suggestion. . . Put your expired film on eBay and sell it to those crazy "lomography" types, who would love to get it, and then buy some fresh film.
02-06-2017, 11:47 PM   #6
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Also you probably will have base density issues. It basically means that you won't have good blacks. At best they will be gray and grainy and at worst grainy with a color cast.
02-07-2017, 12:33 PM   #7
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QuoteOriginally posted by Tony Belding Quote
My suggestion. . . Put your expired film on eBay and sell it to those crazy "lomography" types, who would love to get it, and then buy some fresh film.
Actually, I haven't been having the problem I described a the start, but I have wondered, if I let some film I have now get a little old and I find a bit of color shift in a roll, is there a way to correct it -- if I have a couple more rolls of the same thing left.

There do seem to be some folks crazy for expired film, seeing how film 16 years old can get priced higher than the same film with an expiration date of 2017-18. Just look at 3 or 4-packs of common cheap films like Fujicolor c200--half of the time the brand new stuff is cheaper!

I threw out a bunch of old expired film I had about 6-8 years ago. Processing is too expensive now to waste the money developing stuff that is probably already bad. I started freezing some of my film purchases after that. I know, the gamma rays can still fog the stuff right through the walls of the Fridge, but it slows down other aspects of the aging process.

---------- Post added 02-07-17 at 01:34 PM ----------

QuoteOriginally posted by pentaxus Quote
Also you probably will have base density issues.
My wife's been saying that about me for years.


02-07-2017, 03:03 PM   #8
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QuoteOriginally posted by goatsNdonkey Quote
There do seem to be some folks crazy for expired film, seeing how film 16 years old can get priced higher than the same film with an expiration date of 2017-18. Just look at 3 or 4-packs of common cheap films like Fujicolor c200--half of the time the brand new stuff is cheaper!
Expired film is good for testing "new to you" cameras, where you just want to see if the camera produces an image! That's what I use mine for.

Phil.

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