Guidance on "C-41" base not clearing - first attempt at homebrew

GBS · Sep 6, 2020

Hi,

I've successfully developed a half-dozen Vision 3 rolls in ECN-2, still testing that out. Hoped to have more to report, but it's a slow-going affair.

Tonight I tried C-41, rather, C-27 which I got from @stefan4u here:
https://www.photrio.com/forum/threads/color-negative-developer-near-to-c41.42731/#post-612215

I *thought* I mixed everything correctly, but have my doubts now. What are some causes of this? It happened to this roll, and a test strip that was stored separately, so I don't think it's fog. (I omitted Calgon and A905, mixed with distilled. I do not have a pH meter).

(on the left, tonight's process - Superia film. on the right an example of lab-processed Fuji as a comparison)

I re-fixed for 4 extra minutes and that didn't help. Then I processed a roll of ECN-2 (in separate developer) and used the same fixer, and the ECN-2 came out fine. (The fixer I'm using is C-41 fixer my lab gave me to use for tests).

I'm using ferricyanide bleach with lots of washes before and after, plus sodium sulfite in the stop, as well as a sodium sulfite clearing bath after the bleach.

Mr Bill · Sep 6, 2020

GBS said:
I *thought* I mixed everything correctly, but have my doubts now. What are some causes of this?

There are a lot of possibilities. I'd suggest to start out with a short piece of leader, same film as your problem roll. Bleach and fix, only, then wash and dry. Then see if it cleared ok. If it did, you know that your fixer is functional (the bleach step was to take out the possible silver yellow filter layer).

Next take a short strip of unexposed film, develop, bleach, fix, then wash and dry. So it's just like your previous test, except that developer was added. So if the base stain increases, you can probably blame the developer.

This would be a,start.

Donald Qualls · Sep 6, 2020

How long are you bleaching? Ferricyanide bleach is slower working than the EDTA based bleach the commercial lab would be using, and if the film was under-bleached you might still have part of the silver filter layer present (which would appear in the rebates as well as the frames). Try rebleaching, for at least 8 minutes at 100F, followed by a full fixing period?

GBS · Sep 6, 2020

Mr Bill said:
There are a lot of possibilities. I'd suggest to start out with a short piece of leader, same film as your problem roll. Bleach and fix, only, then wash and dry. Then see if it cleared ok. If it did, you know that your fixer is functional (the bleach step was to take out the possible silver yellow filter layer).

Next take a short strip of unexposed film, develop, bleach, fix, then wash and dry. So it's just like your previous test, except that developer was added. So if the base stain increases, you can probably blame the developer.

This would be a,start.

@Mr Bill, Solid test I hadn't thought of. Thank you. I don't have any more film from the problem roll. But I can do that with a different roll from the same batch. Thanks!

Hey @Donald Qualls. Thanks for asking. Bleaching for 3 min, based on the ECN-2 times from from Kodak for that same bleach. I know they're different chemistry, but didn;t think to adjust the bleach time. I'll try to re-bleach for 8 min, then fix--as well as Mr Bill's clip tests. That should help narrow it down. Thanks a ton.

koraks · Sep 7, 2020

It does look like insufficient bleaching at first glance, but as you point out, ECN2 bleach is pretty vigorous and I wouldn't expect C41 film to be harder to bleach than ECN2 film, but I haven't tried the ECN2/ferricyanide bleach on C41 - apart from rescuing an insufficiently bleached part of film on occasion, which did indeed clear fine in ferricyanide bleach.

I'd suggest something along the same lines Mr_Bill does, but I'd also verify if the fix step is successful. So clip a piece off this processed film, fix it for e.g. 10 minutes in fresh 1+4 B&W fixer. If this makes a difference in density (just hold the dried! test clip next to the rest of the film), you know you have a fixer problem to take care of. If this doesn't do anything, re-bleach the same strip and fix consecutively. Again check the difference. If that doesn't yield any change, you know you have to look at either the developer itself, or the interaction between the developer and the bleach. The latter is a bit unlikely to be a problem given your careful wash steps, so all considered, I'd expect the bleach is the most likely culprit for now.

Just to be sure - you're not comparing very outdated film to fresh film in that photo, are you? I often use 20-year old Superia 200 and compared to fresh film, it gives about the same overall density difference.

Also, to get the development consistent, I'd definitely suggest getting that pH meter if you're DIY-ing your developer. I suspect you're waiting for yours in the mail since our last conversation

GBS · Sep 7, 2020

koraks said:
Also, to get the development consistent, I'd definitely suggest getting that pH meter if you're DIY-ing your developer. I suspect you're waiting for yours in the mail since our last conversation

This made me LOL for a lot of reasons. I tell my friends about the fight--er--discussion I started here asking about pH meters. I did get an inexpensive meter and out of the box, both ECN-2 and C-27 were reading really low, 9.6ish. But the ECN-2 had been developing nicely, so I'm going to mix the buffers and calibrate it before I make any decisions based on what it's reading. The reviews say calibration is likely a necessary step, even out of the box, and likely a necessary step often. I only have one set of buffers (for now), so I'm waiting to calibrate until I mix more of both developers.

I appreciate the thoughtful suggestion. I got a few tests done while I still had everything out.

1) rebleached roll in question for 8 minutes, then fixed and rinsed - no change.
2) clip test (new roll): bleach, fix - normal, clear base
3) clip test (new roll, unexposed): develop, bleach, fix - normal, clear base

L- original roll / R- new roll clip test. unexposed and fully processed

I don't *think* the original roll was expired, nor was it exposed to extreme heat, but I cannot say with full certainty since it was a test roll that bounced around a couple cameras over time. Based on the test results from the new roll, I'm starting to suspect the film for whatever reason. Just odd/ironic that it would be my first attempt. I'll shoot a few frames with the new roll and run those through next time--since I know the new rolls is clearing normally.

Thanks a ton.

@koraks rest assured I'm not done here and will include my pH meter trials and tribulations in my full report!

koraks · Sep 7, 2020

Yeah, I think it might just be the film. There's also an interesting streak of cyan fog in that last picture you posted, suggesting something didn't go entirely as planned with that part of the film.
Honestly it looks pretty similar to what I get from my 20 year old (stored refrigerated) superia 200.
I'm not sure if you have ra4 printing capability; if you do, I'd just make a contact sheet of that film and see if contrast and colors come out OK.

GBS · Sep 7, 2020

I meant to mention that I only put a little developer in the test tank. I thought I put more, but it was an old metal lid that leaked badly, so I put in enough to test, then stopped making a mess.

I don't have RA4, but I do have a hybrid method that will enable me to check for usability. I'm totally fine with somewhat experimental images, especially with this roll, but wanted to check in before I process any more since it didn't seem right.

Rudeofus · Sep 8, 2020

I have played extensively with Stefan's C-41 and E-6 soups. I got similar results to yours at first: way too much base density. I tried rebleaching and refixing - the density remained.

Based on these results I engaged in a brief conversation with Stefan about this recipe. He told me, that this formula implies two things:

Rotary processing with a water jacket temperature of 38.0°C/100°F. This means, that the temperature inside the tank is slightly below 38°C/100°F. If you want to process at 38°C inside the tank, Stefan gave me the C-29 formula, which I posted here with his permission.
No prewash, Stefan was adamant about this. This would be the obvious course of action with rotary processing, but people with inversion tanks love a prewash with 38°C water to get the tank temperature up quickly.

One more thing: whenever I mixed Stefan's recipe, and my pH meter would not show precisely the number indicated in the formula, I knew, that either my pH meter was miscalibrated or that I made a mixing error. Nope, I never used this A905 ingredient, and Calgon makes no difference in pH. If you get pH around 9.6, then something has to be off. There are two hydration forms of Potassium Carbonate (which Stefan called "Potash", he meant anhydrous Potassium Carbonate). Whatever happened, assume that your mix is incorrect, if your pH is that far off.

koraks · Sep 8, 2020

Rudeofus said:
He told me, that this formula implies two things:

But how would either of these things cause high base density or constant fog? Especially to the extent shown here?
I'd have to dig up my negatives from my c27/c29 tests, but I don't recall having run into this issue with those formulas.

Rudeofus · Sep 8, 2020

It is normal developer fog. If a developer is designed to be used at 36°C, it will be too active at 38°C.

The more likely explanation for GBS's woes is a mixing error, or a pH meter calibration error. If the pH meter is calibrated (easy test: a 5 g/l solution of Borax in water supposedly gives pH 9.23), developer pH should not be 9.6 right after mixing.

GBS · Sep 8, 2020

Thanks for sharing your experience @Rudeofus
I also have a copy of C-29 in my notes, so I can try that.

I did tank developing at 101º which I didn't realize was for rotary. I'll do another clip test before I throw out my mix, but I believe the one I did running unexposed film through development showed a clear base. Interesting that you had similar issues, so I will keep testing.

My meter is new and reviews suggest it needs calibration. ECN-2 was reading the same, and those negatives are looking good, so I think it's a calibration/C-27 issue. I have one packet of buffer I intend to mix up and check next time. I'll also have to try the Borax buffer. Thank you.

Two questions:
1) I got my chemicals at Artcraft. He said they were anhydrous based on their chemical makeup alone. Can anyone verify? I'm unclear on the difference.
2) which "C-41" formula are other readers/commenters currently using?

Thanks!

Rudeofus · Sep 9, 2020

There is a good chance, that your chems were fine and that your pH meter is off. I already recommended the quick test with 5 g/l Borax. Sigma Aldrich has a great page for self-mixed buffers here. There are some buffers in this list to be made from common dark room chemicals.

Regarding "which C-41?". I have tried a fair amount of formulas, and they all yield scannable and printable negatives. I have yet to evaluate the test strips I processed during these dev runs.

koraks · Sep 9, 2020

Rudeofus said:
It is normal developer fog. If a developer is designed to be used at 36°C, it will be too active at 38°C.

Hm, to be honest, I'm not convinced. It looks way too dense for just general fog caused by a developer of slightly too high activity. If it was due to an overactive developer, then the actual image contrast should have been through the roof, but it doesn't look like it. A 2C deviation would certainly cause problems, but much more subtle than what we see here.

Rudeofus said:
Regarding "which C-41?". I have tried a fair amount of formulas, and they all yield scannable and printable negatives.

Yes, that's also my experience. The differences are quite subtle. They might be meaningful depending on the purpose of the photographer and how critical he/she is of the end result, but in my experiments, it always came out fairly natural looking.

foc · Sep 9, 2020

I may be a little late to this but when I looked at the shot of the two strips of negs, the one on the left look to me like it is the film could be the problem and not a processing error. (just my observation).

Rudeofus · Sep 9, 2020

koraks said:
Hm, to be honest, I'm not convinced. It looks way too dense for just general fog caused by a developer of slightly too high activity. If it was due to an overactive developer, then the actual image contrast should have been through the roof, but it doesn't look like it.

Contrast and density won't go through the roof, since DIR couplers prevent this. Fog, on the other side, is barely affected by DIR couplers.

If you have access to a film scanner with IR based dust/scratch removal, then you can differentiate very easily between developer fog and retained silver: the former is transparent to IR light, whereas the latter is not. With vuescan you can get the IR histogram. If this is silver, the histogram should be very strong in the lower regions. Other scan software may offer similar functionality.

koraks · Sep 9, 2020

Rudeofus said:
Contrast and density won't go through the roof, since DIR couplers prevent this.

Perhaps not through the roof, but things can get pretty contrasty. Still, looks like a lot of fog for a fairly modest activity deviation. I'd be more inclined towards a problem with overall developer oxidation if this is due to the developer.

Rudeofus · Sep 10, 2020

What can I say? A while back I miscalibrated my pH meter (Disodium Phosphate turned out to be dihydrous instead of anhydrous despite the bottle mentioning no water) and created C-27 at pH 10.3-10.4. The resulting negatives look exactly like the ones shown in the OP. Of course, unaware of the excessive developer pH, I rebleached and refixed these negs at once, but all that made no difference. Contrast looks normal, but base density is out of whack.

GBS · Sep 10, 2020

This is all great information. Thanks a ton for everyone's comments.

The negatives scanned okay. Not great, but neither was the camera/lens/lighting. I plan to shoot a few test frames, leaving a few blank and unexposed, and running that through. I'll report back when I get to that step. I also plan to calibrate my meter, but likely not until I mix another batch of ECN-2, as that's mainly what I'm developing now and want the meter to be good when I check that.

Rudeofus said:
If you have access to a film scanner with IR based dust/scratch removal...

I currently do not, but a friend does about 3 hours away. I'll mail him a strip if the issue persists.

koraks said:
I'd be more inclined towards a problem with overall developer oxidation if this is due to the developer.

The mix was only a few days old with air burped out of the storage bottle, so I'm doubting this, although possible.

Question about anhydrous: I got my chemicals from Artcraft in the U.S. On the phone he said they were all anhydrous based on their chemical makeup, but it's my understanding that hydrous/anhydrous is based on whether they've absorbed some water. Does anyone know one way or another if Artcraft chemicals are anhydrous? Thanks!

Donald Qualls · Sep 10, 2020

Some chemicals absorb water out of the air quickly and in quantity (calcium chloride, for instance, will pull so much water out of the air that it dissolves itself, and is used as a dehumidifier), some don't (heavier metal salts, for instance, like silver nitrate). The chemicals you'd use in a C-41 color developer aren't extremely hygroscopic, but they aren't completely impervious to humidity. Generally, if they arrived in sealed containers, and you've kept them sealed except to dispense for mixing, they should be anhydrous enough for your purposes.

The one exception for this, for C-41, might be sodium carbonate; it's commonly sold (for laundry soda) as the monohydrate, because over time both the anhydrous and decahydrate tend to turn into monohydrate if exposed to free air. Sodium hydroxide and potassium hydroxide will react with water and carbon dioxide from the air, but this isn't really "hydration" -- the reaction with carbon dioxide produces sodium or potassium carbonate as an impurity, and the water taken up from the air mostly goes to make that into the monohydrate.

GBS · Sep 10, 2020

@Donald Qualls -- cheers! Thanks a lot. Yes, they arrived sealed and are stored sealed.

I know sodium carbonate would absorb water pretty quickly. I'm making my own as I go by heating baking soda. I'm hoping this will help me avoid keeping any around long enough to (re)absorb water.

Donald Qualls · Sep 10, 2020

@GBS Sodium carbonate eventually converts to monohydrate. I just buy laundry soda, which is already monohydrate, and correct any formulas that call for anhydrous (18 Daltons for H20 isn't much to add to Na2C03 anyway). You can do the same with soda ash for swimming pools if you worry about the effect of the perfume in the laundry soda.

Rudeofus · Sep 11, 2020

How did Sodium Carbonate enter this discussion? It is not an ingredient of Stefan Lange's C-27.

Donald Qualls · Sep 11, 2020

Sorry, @Rudeofus , I wasn't looking at the recipe for the C-27 when I posted -- and sodium carbonate is a component of some C-41 color developer formulae (it's the main ingredient in the Bath B of the Dignan two-bath, for instance). It's also a chemical that's commonly sold a monohydrate but fairly often called out as anhydrous.

GBS · Nov 17, 2020

Hi all.

I hope everyone is safe and doing well! After a longer-than-expected break, I'm back at it with the same/similar problem, this time with some of the variables removed.

This is my current attempt at C27, compared to lab-processed.
First two are C27 at different temps (explained below). Lab is far right (Kodak Gold 400).

Here's what I know:

Bleach: I've been using this same mix for ECN-2 with great results. To further eliminate that variable, my local lab ran my last test through their bleach and fix. No change. I also doubled the bleach time. No change.

Developer: Fresh C27 (500mL - halved 1L mix). Triple checked measurements, distilled water.

pH: metered 10.6 mixed. I brought it down to 10.16 (@koraks ).

Temp: 100ºF/37.8ºC (far left, Superia 400) - very dark base, same results as last time. I read the temp may have been too high, so I tried...

Temp: 98ºF/36.7ºC (center, Kodak Gold 200). Base color way off, base not as dense as warmer development, but images were underdeveloped and colors and contrast were off when scanned.

In summary:
- my local lab bleached and fixed my previous test. No change. So I'm ruling out bleach. My fix is C41 I got from my lab, so I'm ruling that out, too.
- I mixed a fresh batch of developer, checked pH, and got identical/similar results.

I'm at a total loss.

I know C29 and the patent C42 (and a few others) are also recommended, but I'm going a little nuts trying to figure out why my C27 is consistently so far off. If it's one of my chemicals, then the problem will likely persist to the next formula. Could it be the CD-4?

Thanks a ton in advance!

Guidance on "C-41" base not clearing - first attempt at homebrew

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