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  1. #51

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    Quote Originally Posted by Snapshot View Post
    Hi All,

    I've been using acide stop baths for my printing and developing. However, I've been considering using only water as my stop bath for film development. It's my understanding that the advantage that acid stop baths have is they completely arrest further development of the film. With water stop baths, however, there is some development (although greatly slowed) of the film. Nonethelss, it's my understanding that water bath allows the film to develop a small amount, which in some cases could improve acutance.

    Would anyone care to post their thoughts or musing on the pros and cons of water stop baths? Thank you in advance.

    Why not do both?

    Start with water and let the film rest there for a couple of minutes. If there is any increase in acutance from enhanced edge effects with a water stop bath, two minutes should do it.

    Next, pour the water out and pour in an acid stop bath. If it is true that the acid bath prolongs fixer life, you are covered.

    Sandy

  2. #52

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    Stop Bath

    I have used a 1 part vinegar (white) to 15 parts water (distilled) for years, no odor unless you stick you nose in it, no pinholes in film emulsion and it stops development right now, we are not stoping tanks here. Pat

  3. #53

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    Years, ago, I used a very diluted mix of glacial acid acid for stop during film development; my dilution was much less than generally recommended at the time. Due to occasional issues with pinholes, etc, and the use of pyro-type film developers I seemed to naturally migrate away from acid stops to using water only. If you use alkaline-based fixers (e.g. Photo Formulary's TF-4), then acid stop baths really shouldn't be used. My vote is: use water.

    Hope this helps.
    Regards,
    Alan Huntley
    www.silverscapephoto.com

  4. #54
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    Alan;

    Pinholes should not arise from use of stop baths.

    TF-4 is so heavily buffered at the active pH that a dilute acid stop will have little effect on the fix. In fact, the cloudy ppt. in TF-4 concentrate is the excess buffer to protect you from just such usage.

    PE

  5. #55

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    Just today I was re-reading "Essential Darkroom Techniques" published in 1987 by Jonathan Eastland who according to the flysheet was a professional photographer with 18 years of darkroom experience and ran an international news and features agency. He too mentions the pinhole effect but qualifies it like PE by stating too strong an acid bath may( not will) create such an effect.

    He goes on to say that he found that the very weak effect of development action from the use of a water bath seems to have the effect of enhancing shadow detail without increasing neg contrast. In this context he was talking about Kodak's HC110 which has a syrupy consistency even at working strength and a tendency to stick to the emulsion, hence its continued effect in the water bath. Unfortunately he doesn't expand on the correct water bath process for this effect so there's no way of knowing how long the film was in the water bath.

    Interestingly Mr Eastland does not say he ever had a problem with a proper strength bath nor that he ever had a proplem with an over strength acid bath.

    When books are written it is often the case that the authors reflect the then thinking and in the context of photography, the state of films then and maybe for a few years before.

    PE. Could it have been the case that until some time in the 80s, films were more susceptible to pinholes that has been the case more recently? Hence the acid bath creating pinholes issue

    I used to use an acid bath for film but more recently have switched to water. It's cheaper and easier. It seems to me that if the dev time has been something like 10 mins or even more and the tank is drained properly and immediately filled with say 250mls of water, swilled round and dumped in a matter of seconds then any effect of continued dev in what is a very dilute dev must be very small and effectively eliminated on the second fill and dump.

    I normally use 4 fill and dumps before the fixer and haven't seen any difference in the negs compared to using an acid bath.

    pentaxuser

  6. #56
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    There have been virtually no documented cases of pinholes from carbonate developers and acid stops or fixes. Eaton gives it a passing mention in his textbook but that is about it.

    When a film is too soft and is hit by acid after a carbonate developer, the result is not a pinhole, it is a set of visible blisters. I have demonstrated this in my workshop to the students. The blisters resemble those on human skin from sunburn and when they dry they form either a fish scale like surface or an actual run of the emulsion.

    A pinhole would not be a direct result of the release of gas.

    I have also done this experiment in laboratory controlled conditions to determine if it would be safe to move from Kodalk to Carbonate in the EP-3 process (from EP-C). It had no effect unless the coating was too soft to survive processing without a whole series of other effects.

    Besides, no film from Kodak, Fuji, Agfa or Ilford were that soft for the at least the last 50 years AFAIK.

    PE
    Last edited by Photo Engineer; 08-17-2007 at 05:07 PM. Click to view previous post history.

  7. #57
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  8. #58

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    PE. Thanks. Maybe just goes to show how something that may have had a very limited link with an actual happening which itself was then taken out of context becomes to be quoted as fact but is a myth.

    The problem is always that it may have occurred a few times but be due to other factors and a spurious correlation is made.

    In matters much more vital such as medicines one can begin to appreciate why randomised control trials involving 1000s are conducted before any meaningful conclusions are drawn.

    pentaxuser

  9. #59
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    Well, it appears that a water bath doesn't give me an advantage over an acid bath so I'll continue to use acid for consistent results. However, I'm experimenting with pyro developers and a water stop bath is recommended so I'll use water in those circumstances. Thanks for the responses everyone.
    "The secret to life is to keep your mind full and your bowels empty. Unfortunately, the converse is true for most people."

  10. #60

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    Quote Originally Posted by mhv View Post
    Water bath after developer has never killed anyone,
    many people use it, and as many people use stop bath.
    But not as many use no stop what so ever.
    I don't bother with it at all. Develop then fix,
    film and paper. I use all chemistry one-shot so
    am not concerned with a build up of developer
    in the fixer. Also ph shift is no issue. An acid
    stop is for the purpose of maintaining the
    acidity of an acid fix.

    The short rinse in an acid stop does not wash out
    the developer any quicker than plain water but the
    acidity of the fixer keeps the accumulated developer
    in the fix from being active.

    The accumulation of developer is an issue with those
    who use an alkaline fixer where-in the accumulated
    developer is always active. Dan



 

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