C-41 (Lorr), I'm mixing Part C

Discussion in 'Color: Film, Paper, and Chemistry' started by kmphoto, Jun 14, 2018.

  1. kmphoto

    kmphoto Member

    Messages:
    21
    Joined:
    Apr 22, 2011
    Shooter:
    4x5 Format
    Ok Folks..............
    I have a over abundance of C41 (Lorr) developer with "bad" part C, so I'm mixing part C.

    I am using this formula to mix the developer.
    Stock Replenisher for 2 liters of solution:

    Water 70-100 degrees 1600ml
    Part A 160ml (Lorr) developer
    Part B 25ml (Lorr) developer
    Part C = 21 grams Sodium Sulfite
    10 grams CD-4 (Photographers Formulary)
    Water to make 2 liters
    Ph 10.1
    -------------------------------------------------------------
    I then use the required amount of stock solution and add "starter" to make 1 liter of working solution.
    Adjust Ph to 10.1
    I finish using C-41 Kodak stop, bleach & fix.
    ------------------------------------------------------------------------------
    My Questions:
    1) My negs seem to be lacking in contrast and a bit weak.
    2) There seems to be a (color shift/cross over) to the magenta/green side.

    Do you have any thoughts on this before I run another test????
    Thanks for any thoughts.....


     
  2. RPC

    RPC Member

    Messages:
    1,090
    Joined:
    Sep 7, 2006
    Shooter:
    Multi Format
    The Part C sodium sulfite of 21 grams is 10.5 grams per liter, which is quite high compared to the sulfite level in C-41 formulas I have used or seen, which is about 4 grams or less per liter. Sulfite is a preservative in developers but in color developers, too much will interfere with dye formation. That may be your problem. There may be sulfite in one of the other parts as well, probably part A. In Part C labels I have seen, bisulfite is present as well as CD-4, but not sulfite and certainly not that much. Where did you get that figure? Do you also add water to the stock solution along with the starter?
     
    Last edited: Jun 15, 2018
  3. Rudeofus

    Rudeofus Subscriber

    Messages:
    3,402
    Joined:
    Aug 13, 2009
    Shooter:
    Medium Format
    I agree with RPC, this part C formula looks very odd. I would expect part C to contain CD-4 and a trace amount of Sodium Metabisulfite. You can probably leave out the Sodium Metabisulfite from your part C concoction if you mix fresh.
     
  4. OP
    OP
    kmphoto

    kmphoto Member

    Messages:
    21
    Joined:
    Apr 22, 2011
    Shooter:
    4x5 Format
    RPC, I’m not sure where I got that amount of sodium sulfite, I have a pile of notes print outs off the web.
    I will remix, switch to sodium metabisulfite and cut the amount.
    I recalibrated my Ph meter last night and found it was reading (+.10) to high.
    I’m sure that’s part of it too.
    Thanks for weighing in also Rudeofus…..
     
  5. Mr Bill

    Mr Bill Member

    Messages:
    680
    Joined:
    Aug 22, 2006
    Shooter:
    Multi Format
    No, don't use metabisulfite (nor bisulfite); this will lower the pH of your final mix such that you will have to make an upward adjustment. It's simpler to do as Rudeofus says, using only sulfite.

    Like RPC says, color developers are sensitive to the amounts of sulfite, because it interferes with the formation of the color dyes. You need SOME to help protect the developing agent, but too much is also bad. So go by an actual formula; don't just wing it. It's probably ok to be off by ten or twenty percent, but not by a factor of two or three times.
     
  6. Rudeofus

    Rudeofus Subscriber

    Messages:
    3,402
    Joined:
    Aug 13, 2009
    Shooter:
    Medium Format
    I actually recommended Sodium Metabisulfite over Sodium Sulfite if you want the part C concentrate to have meaningful shelf life. The pH change from 0.1 g/l Sodium Metabisulfite is almost none, given the presence of >30 g/l Sodium Carbonate. That's a mighty buffer!
     
  7. OP
    OP
    kmphoto

    kmphoto Member

    Messages:
    21
    Joined:
    Apr 22, 2011
    Shooter:
    4x5 Format
    Ok I understand.
    I have both sodium sulfite and metabisulfite & can try it both ways in tests.

    Kodak calls part C. 4-(N-Ethyl-N-2-hydroxyethyl)-2-methylphenylenediamine sulfate.
    (I can’t even say it)………………..

    One last question:
    How many grams per liter of either chemical would be used, 4 grams???
    Thanks
     
  8. Mr Bill

    Mr Bill Member

    Messages:
    680
    Joined:
    Aug 22, 2006
    Shooter:
    Multi Format
    Hi, I should be clear that I'm specifically talking about mixing directly to a working replenisher (or tank solution), not trying to reproduce a part C for storage.

    Also, I have not looked at the MSDS, which I'm guessing is what you're using to estimate the part C makeup. But if 0.1 g/l of the metabisulfite is all that's there, then I'd say it's probably not even worth bothering to add it to the working mix (again, I specifically am not talking about making a part C concentrate).

    Something to understand is that either of these will get you to the same result after adjusting pH. Regardless of which you use, if the solution is at a relatively high pH, most of it will be in the form of the sulfite ion. If you then lower the pH of that same solution, by adding an acid, then it will shift to the form of the bisulfite ion. And vice versa. So I just consider that if you add bisulfite to the high-pH color developer you may need to add something else to raise the pH back up. So I would personally just stick with sulfite for the addition, rather than metabisulfite (which, fwiw, gives the same results in a water solution as bisulfite).

    I'd say your best bet is to stick with the formula given here -
    https://www.photrio.com/forum/threads/c-42-is-kodaks-home-version-of-c-41.89135/#post-1191785

    But... the standard LORR package supplies all the sulfite you need. If, as Rudeofus suggests, there is only a tiny amount of sulfite ion supplied by part C (via the metabisulfite) then the obvious conclusion is that most of the sulfite is contained in another part, which you DO have. So I'm not sure that you even need to add any further sulfite. Note that I do not have any actual knowledge of the LORR packaging makeup; just suggesting something to be careful about.
     
  9. RPC

    RPC Member

    Messages:
    1,090
    Joined:
    Sep 7, 2006
    Shooter:
    Multi Format
    If I read all the above correctly, I think the consensus here would be to simply mix as in your original post, but do not add any additional sulfite (all you need is probably in Part A), bisulfite or metabisulfte, then adjust the pH.
     
  10. Rudeofus

    Rudeofus Subscriber

    Messages:
    3,402
    Joined:
    Aug 13, 2009
    Shooter:
    Medium Format
    If you look at Kodak's E6 5l Kit, it contains a bottle of 235ml CD part 2 concentrate. These 235ml of Kodak E6 CD part 2 concentrate contain roughly 41.5 g CD-3 and 1.5 g Sodium Metabisulfite. I would therefore not immediately dismiss that possibility out of hand. Obviously there can't be much more Sulfite/Metabisulfite in solution, since the low pH would drive out Sulfur Dioxide. This ridiculously low amount of Sulfite/Metabisulfite is not going to have much of a photographic effect, but it will likely prevent excessive oxidation of CD-3, the same way it protects lith developer from going bad too soon.
     
  11. Mr Bill

    Mr Bill Member

    Messages:
    680
    Joined:
    Aug 22, 2006
    Shooter:
    Multi Format
    But Rudi, to be clear you're talking about making a Part C concentrate, right? I've not been speaking of the concentrate, but rather the actual working tank solution (or replenisher).

    I personally would not try to make an LORR part C concentrate without seeing a good reason or benefit to it. There may well be some unexpected trickiness to it. Remember that MSDS don't necessarily show everything that's there.
     
  12. OP
    OP
    kmphoto

    kmphoto Member

    Messages:
    21
    Joined:
    Apr 22, 2011
    Shooter:
    4x5 Format
    From the original post:

    I have changed things running new film tests with pretty good results.

    For 1 Liter C-41 (Lorr)
    Water 70-100 degrees 800ml
    Part A 80ml (Lorr) developer
    Part B 12.5ml (Lorr) developer
    Part C = 5 grams CD-4 (No Sodium)
    Water to make 1 liters
    Ph 1.4

    With all the input from you……..
    I thought I’d try a scratch, with no sodium of any type for this test.
    I figured I could add some if it didn’t work.

    The test came out pretty good.
    With no swing of color cross.

    I know that this is not a purist mixture.
    But I think I can make this work, perhaps with a tweek?

    I guess...............?
    "If, your happy with it, use it"…
    If I come across something better....
    I’ll let you know.
     
,