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  1. #1

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    A peculiar happening: Film entirely fogged by developer

    For no better reason than I had the materials on hand, I've developed a couple of rolls using the formula mentioned here: http://www.apug.org/forums/viewpost.php?p=851853

    Quote Originally Posted by Photo Engineer View Post
    This is a very clean working developer, never sold, but used internally for testing photographic emulsions. It is a pure surface developer and does not have any solvent effects on buried image.

    Elon-------------2.5 g
    Ascorbic Acid---10.0 g
    Kodalk----------35.0 g
    KBr--------------0.4 g
    Water to 1 liter

    pH 9.8

    Note the use of decimals.

    PE
    Because of the extreme difficulty of obtaining Kodalk (Sodium metaborate) in the UK, I substituted Sodium Hydroxide + Borax as per this thread http://www.apug.org/forums/forum37/4...tml#post485718 ; I've done this a couple of times now with no unexpected results.

    I'm satisfied that I assembled the developer solution correctly, and I have used the Metol, KBr and Ascorbic acid recently for other developers with no unexpected results.

    My first roll through (a week or two ago) was fine, and in fact was good enough to prompt me to try it again this evening, so I made up another batch of EAA ... but tonight I had an unexpected and puzzling result.

    I used 5 minutes @ 20C as a starting point. My first 12-frame roll (135, from bulk) came out of the tank entirely fogged - the rebates were jet black; it looked like I had put it through a reversal process. Images were just discernible within the frames.

    Assuming I'd somehow exposed the film when rolling it or when loading the tank (both tasks had however been carried out in total darkness, but one never knows), I tried another - with exactly the same result.

    I tried a third roll from the same batch of film with a different developer - no problems; all developed as expected, clear rebates.

    Then I tried the EAA again, but this time with a strip from a commercially loaded cassette (Lucky 100 as it was to hand and cheap); Same result - complete fogging, with just discernible images present. (I'd split the Lucky into three strips of 12, and tested the other strips with a different developer - all developed OK)

    The obvious conclusion is that there was something awry with this batch of EAA, perhaps as a result of inadvertent contamination.

    SO ... what contaminants might have produced this curious effect? I know that there are "fogging developers" used for reversal purposes, and I know that Sodium dithionite and Stannous chloride are used for those purposes, but I possess neither.

    I post this as a curiosity rather than an earnest enquiry, and I'm sure someone will want to tell me I'd be better off using D76, or that nobody without a PhD in Chemistry should mix developers, but it would be nice to have some sort of hypothesis to explain what's occurred.

  2. #2

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    Boy, I'm no chemist, but I know that the high-contrast developers with sodium hydroxide in them (like Kodak D-8) are blisteringly active. Typical developing times in D-8 are 2 minutes. So my guess would be that there was some non-reacted sodium hydroxide in your homebrew sodium metaborate.

    I've never used D-8, but I mixed some D-19 recently and used it, and noted that when I poured in the stop bath, there was a lot of gas evolved, it was trying to push the lid off the Nikor tank. Anything similar happen to you, showing that the developer was a strong base?

  3. #3

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    Good point from John Shriver, especially when I read the post linked by the OP...

    'If the crystals loose the borax whitish look and become kind of transparent (metaborate crystals), you've overdone the hydroxide, and the solution pH will be higher than it should be.'


    What was the pH of the developer you mixed in this 'strange' batch? A few pH test-sticks might be handy to keep things under control, as the perfect moment during the reaction may be difficult to judge without them.

  4. #4

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    thanks for your replies, gentlemen.

    I only use a water stop, so no fizzing noticed. pH sticks or strips might indeed be handy, so perhaps I'll head off to eBay.

    I did also wonder about the pH being the culprit but on the other hand, I have never heard of unexposed emulsions being completely developed in this way, regardless of pH.

    [On the other hand again, I managed to shoot film for the best part of 35 years without picking up a developing tank, and I'm only about 18 months into this, so my not having heard of something doesn't really count ]

    I might give it another go, but instead of using my homebrew metaborate, stick to mixing weighed quantities of Borax and Sodium Hydroxide; the main reason for not having done so anyway is because the moment I take the top off my hydroxide jar and weigh it out, I can almost see it sucking up atmospheric water and I was concerned that this would throw off the proportions.

    (That's why I started another metaborate thread here http://www.apug.org/forums/forum37/1...ate-again.html in the hope of getting useful some answers; unfortunately all I got was the usual "why bother/don't bother" responses, followed by the thread mutating into yet another abstruse disquisition on 4-mol vs 8-mol versions of borates.)

  5. #5
    Rafal Lukawiecki's Avatar
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    Just a thought: did you dissolve sodium hydroxide and borax together, separately from the rest, before adding that solution to the solution already containing Metol and Ascorbic Acid, or did you add hydroxide as the 3rd ingredient, that is straight after ascorbic acid? I wonder if this could have an impact, perhaps a resident chemist would weigh in.

    PS. I believe you would get significant all-over chemical fog if the developer were so out of balance, that the restrainer would not do its job.
    Rafal Lukawiecki
    See rafal.net | Read rafal.net/articles

  6. #6

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    Thanks Rafal.

    Quote Originally Posted by Rafal Lukawiecki View Post
    PS. I believe you would get significant all-over chemical fog if the developer were so out of balance, that the restrainer would not do its job.
    that's a very interesting comment.

    As to your question, No the metaborate solution was added as the third component, with the KBr last.
    According to my dilution calculations (which may be incorrect), the required 35g/l of metaborate is equivalent to 140ml of a 25% solution + 860ml diluent.

    However I have subsequently found a comment (can't find it again now), by none other an expert than PE, to the effect that Ascorbic acid can be temperamental in developers. Or at least that is how what I understood him to be saying.

    As EAA is a "lab" developer, and my kitchen is certainly not a lab, nor I a lab technician, it's perhaps not surprising I've had inconsistent results.

  7. #7
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    Quote Originally Posted by pdeeh View Post
    However I have subsequently found a comment (can't find it again now), by none other an expert than PE, to the effect that Ascorbic acid can be temperamental in developers. Or at least that is how what I understood him to be saying.
    Ascorbic Acid can be quite temperamental, but in the opposite direction: sudden death of developer, i.e. a jump from almost normal development to none at all in a very short time frame and for no apparent reason. Kodak did find solutions to this issue (DTPA, HEDP), and a a result Xtol working solution lasts for several months, but most home brew recipes don't include a suitable sequestering agent and therefore lack stability. But this issue doesn't seem to happen here in your case.

    When I mixed my own experimental developers, I did notice that developer fog doesn't come in small doses: either your negs are more or less fog free, or fog jumps in your face. As a result, even small deviations from the correct recipe can cause high fog levels which make your negs barely printable.

    Here is what I would do in your situation:
    • Do yourself a favor and get a pH meter. These are dirt cheap and can be gotten from many sources. pH strips are nice for getting into the ball park, but a pH meter gives you real numbers down to 0.1 or 0.2 pH, depending on what you spend.
    • Until that pH meter arrives, add more and more Borax or Boric Acid to that dev and test with unexposed film clips until you no longer get fog.
    Trying to be the best of whatever I am, even if what I am is no good.

  8. #8

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    Quote Originally Posted by Rudeofus View Post
    Do yourself a favor and get a pH meter. These are dirt cheap and can be gotten from many sources. pH strips are nice for getting into the ball park, but a pH meter gives you real numbers down to 0.1 or 0.2 pH, depending on what you spend.
    Good advice since making your own Kodalk can be tricky. The only good way is to accurately measure the amounts of lye and borax. There is a couple of methods based on observation that are rather worthless. Even a small excess of lye can really throw off the pH of the final product. It is therefore better to err on the side of too little rather than too much lye.
    Last edited by Gerald C Koch; 10-13-2013 at 02:40 PM. Click to view previous post history.
    A rock pile ceases to be a rock pile the moment a single man contemplates it, bearing within him the image of a cathedral.

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    Rudeofus, Gerald, thank you.

    I can accurately weigh chemicals, but as I say the hydroxide rather slurps up moisture. However as that would cause the error to be on the low side (i.e. less hydroxide by weight), that might be a safer approach.

    Perhaps for more commonly used developer formulae which were intended to be made up by hamateurs, there is a bit more leeway in the pH range they will tolerate? but as EAA was used for emulsion testing at Kodak, I expect the tolerance was rather more exacting, let alone the difference in materials quality & storage, and process control.

    I find it all fascinating, in the same way as I found it fascinating when I learned how the protein chains coagulate when frying eggs; the latter changed the way I fried eggs, and every time I learn a bit more "meta-chemistry" with regard to developers, it changes the way I approach photography a bit; I hope for the better ...

  10. #10
    Rudeofus's Avatar
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    Quote Originally Posted by pdeeh View Post
    I can accurately weigh chemicals
    You can weigh chemicals accurately but you may or may not know the exact composition of them. Most chems are only of technical purity, and whatever else comes with them can change the final result.

    Quote Originally Posted by pdeeh View Post
    Perhaps for more commonly used developer formulae which were intended to be made up by hamateurs, there is a bit more leeway in the pH range they will tolerate?
    Wasn't it quite common to have a stock solution of 1% KBr or whatever back then (I wouldn't know but the Darkroom Cookbook suggests so)? And weren't published dev times generally considered starting points from which people had to fine tune to their needs individually?

    What has changed is that we have dozens of films and hundreds of developer recipes readily available, yet expect usable results from random combos at the first attempt.
    Trying to be the best of whatever I am, even if what I am is no good.

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