Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,220   Posts: 1,532,318   Online: 964
      
Page 5 of 6 FirstFirst 123456 LastLast
Results 41 to 50 of 52
  1. #41
    RPC
    RPC is offline

    Join Date
    Sep 2006
    Shooter
    Multi Format
    Posts
    367
    So, where do you stand now. Have you determined whether you used developer or replenisher, and whether it was mixed properly?

  2. #42
    keyofnight's Avatar
    Join Date
    Sep 2012
    Location
    Seattle, WA
    Shooter
    35mm
    Posts
    86
    Quote Originally Posted by Mr Bill View Post
    More than likely, you somehow botched the developer. I say this because fixer is pretty hard to mess up. About the only other possibility is that you are somehow fogging the film during development.
    Yes—we just ascertained that later on in the thread. Foc, rudeofus, RPC, and clayne suspected that I may have overdeveloped them; and rudeofus noticed that I developed them in replenisher instead of tank solution. Flexicolor SM is nice in that it doesn't need starters, but Kodak never published ratios for mixing tank solutions, just replenishers. I just assumed they were the same for this particular chemistry. They are not the same.

    You're right about the test strip. I won't bother with it until I develop negs that look like they're in the ballpark.

    I just tested the fixer as you suggested, and the fixer is just fine.

    Quote Originally Posted by RPC View Post
    So, where do you stand now. Have you determined whether you used developer or replenisher, and whether it was mixed properly?
    Yes. I most certainly used replenisher instead of tank solution, and that caused overdevelopment. Now that I have the right instructions, I'm sure I'll get some measure of success next time.

  3. #43
    keyofnight's Avatar
    Join Date
    Sep 2012
    Location
    Seattle, WA
    Shooter
    35mm
    Posts
    86
    Just to be on the safe side, I decided to create a spreadsheet to keep track of the mixture amounts. I noticed something: there is actually more of components B (hydroxylamine sulfate) and C (CD-4 and Sodium Bisulfite) in the tank solution than in the replenisher solution. This makes me a little nervous that my basic math is off or that my spreadsheet is wrong…but I know film chemistry is not always intuitive. Either way, it's clear that I was using the wrong mixture.

    Could one of you take a look and see if I've made a mistake?
    Attached Files

  4. #44

    Join Date
    Aug 2006
    Shooter
    Multi Format
    Posts
    325
    Hi, on rereading the thread, I now see that the developer issue was raised several times, in particular by RPC who also pointed out that bleach shouldn't have to work on D-min areas.

    Regarding your latest post, I don't see any calc errors. If anything is wrong, I'd guess it to be from the "label art."

    Your results show that the Part B proportion used in TANK solution is much higher than in REPLEN. The most obvious explanation for this is that Part B contains restrainers (similar to byproducts from the film). This would also explain why SM chemicals don't need a "starter;" the key ingredients are already available by rebalancing the existing components (you increase the component containing the "starter chemicals").

    As to why the mix, generally, doesn't seem right, my best guess is that the fresh tank solution was made empirically. That is, they tried to avoid having a separate "starter," so just found a best approximation by trial and error. (As a wild guess, the unexpected reduction of part C might be to try to keep the preservative package balanced, assuming the HAS was in part B.)

    I have quite a lot of color neg processing experience, and have NEVER found a freshly made tank solution to match a seasoned mix. Generally they are somewhat close, but not good enough for critical matching work (anyone who knows what a VCNA or PVAC is, will know what I mean). The fresh processor solutions will always show shifts in the process control charts as they become seasoned. (In fact, different film mixes will shift the control chart plots to different positions.)

    Anyway, I think there is a fairly good liklihood that Kodak came up with the final tank solution mix as a result of actual trials. But I would also be suspicious that the label art is not correct.

    If I were in your shoes, I'd just mix per your calculations, and run the control strip for a "reality check" (I'd be pretty surprised if everything was within "spec limits). If you don't know what everything means on the control strip, an actual film test is probably more useful.

  5. #45
    keyofnight's Avatar
    Join Date
    Sep 2012
    Location
    Seattle, WA
    Shooter
    35mm
    Posts
    86
    Quote Originally Posted by Mr Bill View Post
    Your results show that the Part B proportion used in TANK solution is much higher than in REPLEN. The most obvious explanation for this is that Part B contains restrainers (similar to byproducts from the film). This would also explain why SM chemicals don't need a "starter;" the key ingredients are already available by rebalancing the existing components (you increase the component containing the "starter chemicals").
    Excellent. That was my hunch given what I could Google about hydroxylamine sulfate. Thanks for corroborating—it makes me feel a lot better.

    Quote Originally Posted by Mr Bill View Post
    I have quite a lot of color neg processing experience, and have NEVER found a freshly made tank solution to match a seasoned mix. Generally they are somewhat close, but not good enough for critical matching work (anyone who knows what a VCNA or PVAC is, will know what I mean). The fresh processor solutions will always show shifts in the process control charts as they become seasoned. (In fact, different film mixes will shift the control chart plots to different positions.)
    I see! I read about this in the Z101 publication, but they don't say much about how long it takes for a working solution to become well-seasoned. How long does it take?

    Quote Originally Posted by Mr Bill View Post
    If I were in your shoes, I'd just mix per your calculations, and run the control strip for a "reality check" (I'd be pretty surprised if everything was within "spec limits). If you don't know what everything means on the control strip, an actual film test is probably more useful.
    Okay! Cool. I'll develop another test roll of cheap film. If it comes out looking somewhere in the ballpark of normal, then I'll run a test strip just for kicks. I don't know what control strips mean, but it's about time I learned.

  6. #46

    Join Date
    Aug 2006
    Shooter
    Multi Format
    Posts
    325
    Hi, the "starter chemicals" are most likely bromide ion and a tiny bit of iodide ion (from NaBr or KI), among other things. They may not show up on MSD sheets because of the low concentrations. I'm just guessing that they're in Part B to explain the otherwise odd mix ratio.

    Hydroxylamine sulfate (HAS) is generally considered to be part of a preservative package. It seems desirable to have it in some sort of balance with other preservatives; this is the basis of my wild guess as to why the Part C is also reduced somewhat (the assumption is that other preservative components are in Part C). I don't know the mechanisms, or have any real basis for saying this, though (at least that I recall); it's more of a hunch, or perhaps better said, a "wild guess."

    Regarding "seasoning," a general rule of thumb is that two tank-turnovers is pretty near being fully seasoned. So if you had a 1-gal processing tank, this would mean running 2 gallons of replenisher through it. It takes longer than you might think, but unless you're really trying to keep your control plots screwed down tight, who cares? If you were to set up for high output, almost like a factory production line, then it would be important, but otherwise, maybe not.

    Learning to interpret problems via control strips can be almost an art, and can be much more complicated than learning how to mix chemicals and develop film. There are example charts in the Z manuals, but I never found them to be too useful past a rudimentary level. If you trust them explicitly, you might, for example, have an over-replenished system (too much developer activity) but finding a match to a Z-manual example chart might imply that your temperature is too high, or that your mix was too concentrated. You have to be careful not to read in more precision than is really there.

    If you want to understand what the control strips are actually showing, a good way to start is to study "characteristic curves" of film a bit. Then imagine the control chart as showing a couple of exposure points on those curves.
    Last edited by Mr Bill; 08-04-2013 at 10:41 AM. Click to view previous post history.

  7. #47
    Rudeofus's Avatar
    Join Date
    Aug 2009
    Shooter
    Medium Format
    Posts
    1,593
    Images
    10
    Mr. Bill, all these starter chemicals and seasoning efforts are meaningless here because keyofnight uses a kit that doesn't have or need these things. He uses a kit that you mix according to (poorly written) instructions, then use for a dozen rolls or so, then discard. Since there is no continuous operation, and temperature control if flaky at best with hand inversion tanks, control strips are mostly pointless.

    The problems, that keyofnight reported, were most likely resolved around August 1st, and with correctly mixed components keyofnight will likely get very nice and printable negatives like most other users of C41 home dev kits including myself.
    Trying to be the best of whatever I am, even if what I am is no good.

  8. #48
    RPC
    RPC is offline

    Join Date
    Sep 2006
    Shooter
    Multi Format
    Posts
    367
    No need to worry about fresh working solution (properly mixed), exactly matching a seasoned tank. They both should meet Kodak specs if a control strip is run, and that's what's important.

  9. #49

    Join Date
    Aug 2006
    Shooter
    Multi Format
    Posts
    325
    Hi Rudeofus. Point taken; I have been meandering.

    However... I started out to answer post #43, where keyofnight, in his pdf file, noticed a discrepancy. The TANK solution is essentially MORE CONCENTRATED than the REPLEN. I figure this cannot possibly be a "correct" formulation.

    I made some guesses as to how this might work, but later looked through some MSD sheets for SM chemicals, and found that my guesses don't work either - the restrainer is in the only part, A, that uses the same amount for both. There is more wrong, but I'll spare you that.

    Since Rudi indicates things are likely solved, but I don't see it, I went back through the entire thread, following the links, etc. About the only thing I come up with is that keyofnight uses a Kodak part# that, per the Z-manual, is specified as a "tank" version. Even though it is called C41 SM, just like the replenisher versions. So my best guess now is that the "tank" version is formulated differently and that there is no point comparing the "tank" vs "replen" mix ratios because they're two different animals sharing the same name. (Wish they would have named it differently, though; SM is supposed to be the plug-n-play machine version where the operator never comes into contact with the chemicals.)

    Anyway, I really don't know if the problem is solved or not. I wouldn't trust it without a confirmation test.

  10. #50
    Rudeofus's Avatar
    Join Date
    Aug 2009
    Shooter
    Medium Format
    Posts
    1,593
    Images
    10
    Quote Originally Posted by Mr Bill View Post
    However... I started out to answer post #43, where keyofnight, in his pdf file, noticed a discrepancy. The TANK solution is essentially MORE CONCENTRATED than the REPLEN. I figure this cannot possibly be a "correct" formulation.
    Looking through the MSDS and comparing what I see in these with the MSDS of these tank solutions, I could not see Iodide anywhere in the MSDS although it is most likely part of any correct C-41 formula. Given that MSDS don't have to list ingredients that are contained in low concentration, there is a very high chance that the Iodide is contained in one of these parts but simply not listed. We also know that Iodide will readily oxidize to Iodate unless protected by some other compound, and I would expect that HAS does this job in part B.

    All this indicates that part B likely contains Iodide which is a much stronger restrainer than Bromide, and if you add too little of part B you will get fog and other issues.

    And yes, as you stated, a confirmation from keyofnight would be nice, but given that these dev kits generally work well I am quite confident that his next negs will come out fine.
    Trying to be the best of whatever I am, even if what I am is no good.

Page 5 of 6 FirstFirst 123456 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin