Bizarre blotchy, semi-transparent marks on C-41 negatives

[pwadoc]

Hey all, I've encountered a strange problem with my last batch of C-41 negatives, where I'm seeing weird flecks of some semi-transparent contaminant all over the scans. When I look at the film itself, I see what looks like bits of reflective material on the emulsion side. One interesting aspect of these flecks is that they seem to be mostly limited to the 35mm rolls I processed, and only appear in small numbers on the 120 rolls I had in the same batch. This occurred on 3 different rolls, all different emulsions purchased at different time (the example photo is Portra 800), and stored in a freezer. I have a few guesses as to what this is, but I'm wondering if anyone else has encountered something similar.

Here is an example image:

And an enlargement of some of the marks:

Some details about my process:

I use a Jobo ATL-1 to process the negatives with Kodak's Flexicolor chemistry. I mix all of my chemicals with distilled water and use the developer one-shot. I use a stop bath between the developer and bleach, and I re-use the stop, bleach, fixer and final rinse a few times before discarding. I run process control strips, and the strip in this batch actually indicated near-perfect development, less than -0.05 density deviation from the comparison strip for any of the measurements. I've been running film through this process for over a year now, around 300 rolls of 35mm and 120, and this problem has only cropped up recently.

Some guesses about the cause:
1) Some sort of contamination from the rinse water. I don't use distilled water for rinsing, so it's possible there's something in the rinse water that would cause this. These don't look like water marks to me, however.
2) Incomplete bleach or fixing. The flecks are reflective, which makes we wonder of the fixer or bleach was retained in spots. The leak in the canister could have resulted in a diluted bleach or fix, though strangely it had no effect on the developer, as evidenced by the process control strip. This is my leading theory given that the 120 rolls weren't affected as much. They have less surface area than the 35mm, and it's possible the weakened chemicals completed more of the process as a result.
3) ECN-2 remjet contamination. I think this is unlikely as I've done a fair bit of ECN-2 in this processor without problems, I always rinse everything thoroughly (including the feed lines) with clean water after running ECN-2 film, and the marks don't really look like remjet, but I thought I'd mention the possibility.
4) Some sort of precipitate or contamination in one of the chemicals. Not really sure how to narrow this down. I use distilled water to mix all of my chemicals, and swap them out on a regular basis (once every 4 or 5 sessions).

If anyone has encountered something similar, I'd be interested to hear about it.

 

[MattKing]

Try a roll without the final rinse to see if the problem originates there. You can always re-wash and final rinse that roll later.

 

[pwadoc]

Try a roll without the final rinse to see if the problem originates there. You can always re-wash and final rinse that roll later.

Thanks for the suggestion, I will try that! I did refresh the rinse for this film batch, but I refreshed it from 5L of mixed rinse that I've been working my way through for a while, so it's totally possible the rinse is an issue.

 

[runswithsizzers]

Do you use a changing bag when loading the film on the reels?

 

[pwadoc]

Do you use a changing bag when loading the film on the reels?

Yes, I do. Do you think that could be a factor?

 

[runswithsizzers]

Yes, I do. Do you think that could be a factor?

I have not experienced it, but I have read that the coatings on some changing bags sometimes deteriorate and can flake off. Since the coatings on some changing bags are reflective I was just wondering if the reflective spots might be bits of coating from the bag? It is kind of a wild guess long shot, but it is something you could check while we are trying to think of a real answer.

Of course, if that is what is happening, you should also check your changing bag for light leaks!

 

[foc]

The flecks are reflective, which makes we wonder of the fixer or bleach was retained in spots.

I have a few questions, please.

Would it be possible for you to post an image of the neg showing the reflective spots?

Do you always use a reusable stop between dev and bleach?

Try a roll without the final rinse to see if the problem originates there. You can always re-wash and final rinse that roll later.

I think this could be the solution to your problem as Matt has suggested. IMO most problems with spots and marks on the negatives in C41 processing usually occur in the final rinse/stabilizer stage.

 

[pwadoc]

I have not experienced it, but I have read that the coatings on some changing bags sometimes deteriorate and can flake off. Since the coatings on some changing bags are reflective I was just wondering if the reflective spots might be bits of coating from the bag? It is kind of a wild guess long shot, but it is something you could check while we are trying to think of a real answer.

Of course, if that is what is happening, you should also check your changing bag for light leaks!

That's a good suggestion, it was also super hot and sweaty that day, so very possible that something came off the inside of the bag. I will definitely check that.

I have a few questions, please.

Would it be possible for you to post an image of the neg showing the reflective spots?

This is the best shot I was able to manage. You can't see the reflective aspect as clearly here, but you can get a sense of what the stuff looks like on the negative (this is the emulsion side):

Do you always use a reusable stop between dev and bleach?


I think this could be the solution to your problem as Matt has suggested. IMO most problems with spots and marks on the negatives in C41 processing usually occur in the final rinse/stabilizer stage.

Yeah, the more I think about it the more I feel like the rinse could be responsible. I feel like anything that happens in an earlier stage would also have probably washed off in the rinse if it were working correctly.

 

[foc]

This is the best shot I was able to manage. You can't see the reflective aspect as clearly here, but you can get a sense of what the stuff looks like on the negative:

Thank you for posting the photo of the neg strip.

From looking at your image of the neg strip, I don't think it was the changing bag, unless you can see bits falling off the inside when you open it. !

It looks to me like it's the wash or final rinse.
Did you think of soaking the negs in wark water and just a tiny drop of final rinse. Leave them for a few minutes and then very gently rub the neg between your clean thumb and forefinger and see does that dislodge any of the spots. (don't worry as negs are hardy even when wet ! )

You can dry the neg strips by using a paper clip attached to your drying peg/clip and through the sprocket hole at the top and bottom of the strip.

If you do try it can you let us know how you got on, please?

 

[pwadoc]

Thank you for posting the photo of the neg strip.

From looking at your image of the neg strip, I don't think it was the changing bag, unless you can see bits falling off the inside when you open it. !

It looks to me like it's the wash or final rinse.
Did you think of soaking the negs in wark water and just a tiny drop of final rinse. Leave them for a few minutes and then very gently rub the neg between your clean thumb and forefinger and see does that dislodge any of the spots. (don't worry as negs are hardy even when wet ! )

You can dry the neg strips by using a paper clip attached to your drying peg/clip and through the sprocket hole at the top and bottom of the strip.

If you do try it can you let us know how you got on, please?

So I don't have any final rinse on hand, and I won't be able to try this until I get back into my studio, but I just attempted a test with a bit of leader that I clipped from one of the affected rolls and some photo-flo. I rubbed pretty hard but after drying I can still see the material on the emulsion. I also tried earlier with some Pec-12 and a Pec Pad and wasn't able to get any of the stuff off. This is why I was thinking it might have been incomplete fixing, because whatever this is is really hard to remove. It's also possible that it's really embedded in the emulsion.

Editing to add a photo of the film post-rinse, which gives a better view of the substance on the emulsion. It really does look to me like a coating or something that has partially come off?

 

[foc]

So I don't have any final rinse on hand, and I won't be able to try this until I get back into my studio, but I just attempted a test with a bit of leader that I clipped from one of the affected rolls and some photo-flo. I rubbed pretty hard but after drying I can still see the material on the emulsion. I also tried earlier with some Pec-12 and a Pec Pad and wasn't able to get any of the stuff off. This is why I was thinking it might have been incomplete fixing, because whatever this is is really hard to remove. It's also possible that it's really embedded in the emulsion.

Editing to add a photo of the film post-rinse, which gives a better view of the substance on the emulsion. It really does look to me like a coating or something that has partially come off?

View attachment 278930

Your photo shows it up very well. It sure looks embedded in the emulsion.
Could you try refixing the leader piece in your image above, then rewash and use the wetting agent and rub and see?

I just had a thought, do you filter your reusable chemicals like bleach, fix and stop bath?
Fixer can be easier to see any particles floating about, than looking at bleach.

When you took your films from the freezer, were they in the closed canisters and allowed to thaw out in the fridge to avoid condensation?

 

[pwadoc]

So I tried a bunch of things on strips of the film, re-bleaching, re-fixing and re-washing and nothing seemed to help. I finally took a look at it under a microscope, and from what I can tell the spots are actually emulsion damage. It almost looks like the film was evenly splattered with something that dissolved through the emulsion layer. I'm at a bit of a loss to explain what could have done that, but I'm going to replace all of my chemicals and start drying the film on the reels in a PVC tube to see if that makes a difference. Thanks for all of the suggestions!

 

[BrianShaw]

Do the spots rub off if you rub them with your finger or a microfiber cloth? Probably not if they are emulsion damage. But I also noticed in the post #8 image what looked like scratches in the rebate. Odd...

 

[pwadoc]

Do the spots rub off if you rub them with your finger or a microfiber cloth? Probably not if they are emulsion damage. But I also noticed in the post #8 image what looked like scratches in the rebate. Odd...

I've been handling that rebate a lot and it is pretty scratched up. I've tried several things to remove the spots, including PEC-10 and alcohol, and no dice. Under magnification they are pretty obviously holes in the emulsion. I tried to take a photo through the microscope but couldn't get anything usable.

 

[dmtnkl]

So I don't have any final rinse on hand, and I won't be able to try this until I get back into my studio, but I just attempted a test with a bit of leader that I clipped from one of the affected rolls and some photo-flo. I rubbed pretty hard but after drying I can still see the material on the emulsion. I also tried earlier with some Pec-12 and a Pec Pad and wasn't able to get any of the stuff off. This is why I was thinking it might have been incomplete fixing, because whatever this is is really hard to remove. It's also possible that it's really embedded in the emulsion.

Editing to add a photo of the film post-rinse, which gives a better view of the substance on the emulsion. It really does look to me like a coating or something that has partially come off?

View attachment 278930

I had similar flakes like in the photo of post #10 when i was developing with Tetenal's Magic Box E6 chemistry. Strangely enough, it seemed to affect only kodak films, and more specifically Ektachrome 100 and cross processed Ektar 100. My theory was that kodak's emulsions get really soft while developing and the flakes stick, while fuji's emulsions soften enough for the chemistry to work, but not for massive amounts of flakes and debris to stick. Of course this is only speculation on my part.

Once i started running my working solutions through coffee filters before putting them in their final working bottles, the problem went away. During development, i also use a paterson water filter while washing with running water.

 

[pwadoc]

An update for anyone who encounters this in the future, the cause of the problem was a bunch of tiny crystals that had formed in the Flexicolor developer replentisher I was using. I'm not sure how it formed, since the chemicals had not expired prior to mixing and I mixed with distilled water, but something caused the developer to start to crystallize. I was able to reduce but not eliminate the crystals by heating and stirring it. My studio space does tend to get pretty hot, since it's located on the top floor of a building without air conditioning, but I don't think it could possibly be hot enough to affect the developer in that way.

 

[koraks]

So good that you found the cause! I found this one particularly puzzling.

My studio space does tend to get pretty hot, since it's located on the top floor of a building without air conditioning, but I don't think it could possibly be hot enough to affect the developer in that way.

I think the opposite is more likely: some chemistry (developer concentrates mainly) tends to crystallize out at low temperatures. It's possible your developer just caught a cold. It's not always possible to redissolve the crystals; you're lucky it worked in your case.
Do you store your developer replenisher as at working strength or as a concentrate?

 

[pwadoc]

So good that you found the cause! I found this one particularly puzzling.

I think the opposite is more likely: some chemistry (developer concentrates mainly) tends to crystallize out at low temperatures. It's possible your developer just caught a cold. It's not always possible to redissolve the crystals; you're lucky it worked in your case.
Do you store your developer replenisher as at working strength or as a concentrate?

Yeah this was a tricky one to figure out. Generally I mix up 5L of the dev replenisher, following the instructions on the 3 bottles to get the concentrate, and use Tetenal Protectan to force as much air out of the storage bottles as possible. I then mix working strength developer 1L at a time when I need to process film, which actually works out perfectly as the Jobo bottles I use take about 900mL of chemistry. I've can get the chemistry last a few months this way, and I throw a control strip in with my film batches and test it with a densitometer to make sure the chemistry isn't going bad, among other things.

I'm honestly baffled as to how the developer replenisher ended up crystallizing. My guess is that temperature in my studio haven't dropped below 80F since I've mixed that particular batch, and they're probably a lot higher most of the time.

 

[koraks]

Very odd indeed! Do you use tap water by any chance? I can imagine a precipitate forming due to the presence of calcium in the tap water. It wouldn't crystallize though; usually it settles at the bottom as a mikly white/murky layer.
I've had RA4 developer concentrate crystallizing out like crazy, but that's a different situation. I'm surprised C41 developer replenisher is capable of doing the same.

 

[pwadoc]

Very odd indeed! Do you use tap water by any chance? I can imagine a precipitate forming due to the presence of calcium in the tap water. It wouldn't crystallize though; usually it settles at the bottom as a mikly white/murky layer.
I've had RA4 developer concentrate crystallizing out like crazy, but that's a different situation. I'm surprised C41 developer replenisher is capable of doing the same.

Nope, I used distilled water, and these were very clearly crystals suspended in the solution. I actually just finishing a few tests with the affected developer, and while I could still see a few crystals in the stuff I had heated and stirred there were none left on the emulsion. Filtering the developer with a coffee filter completely eliminated all visible crystals.