stop bath????

Discussion in 'Large Format' started by emile_de_leon|9, Jan 16, 2003.

  1. Hi all,
    Lately I've been using water instead of stop bath for my prints
    and my lungs are thanking me in spades for it! I'm thinking about
    eliminating the stop bath for sheet film too if that is possible and
    wanted to know what you fellow LF, fume&lung challenged,
    photographers think about that course of action? Thanks.
     
  2. I never use stop for film always just water, I feel stop is little abrupt in film processing. You may want to rethink not using it for prints though since when your doing a big printing session you are going to kill your fix quickly.
     
  3. Some do not use an acid stop-bath but the other option is a citric acid bath - smells of oranges & lemons... well... not quite, but is much less acrid than the usual acetic acid. Best to keep it in the fridge between use or just make up enough for one session as it seems to oxidize quickly.

    Cheers,
     
  4. Emile: There are inexpensive "odorless" stop baths available which are not unpleasant to use. I'm not sure they are truly odorless but they are close. Clayton has such a product and I believe the Arista line now includes one too. If you mix a fixer like F6 and use that too, the unpleasant odors, even with relatively poor ventilation, won't bother you. I'm not offering medical advice here, of course. A tray with water slowly running would probably work fine too.
     
  5. I've never used stop bath, just a water rinse. No adverse effects. I just compensate marginally in my development cycle, though it probably doesn't really matter in the least.
     
  6. There's nothing like the smell of stop bath in the morning, while you play "Flight of the Valkyries" mixed with helicopter flight noise on the darkroom stereo. ;-)

    Seriously, I've switched to Ilford odorless stop bath. Cheaper than properly ventilating the darkroom, but I'm not sure if there are actually any long-term health benefits from not being able to smell what I'm breathing.
     
  7. I also recommend Ilford Ilfostop. It is convenient to store and mix,
    does not produce pinholes in film, in my experience (I had some
    pinholing with acetic acid), and does not smell bad, if at all.
     
  8. May sound corny, but you do need stop bath to stop the developer's action, unless you decided not to! :) Odorless stop bath, e.g. from Tetenal, is a good option.
     
  9. Stop bath for developing film is usually considered less important than for developin prints. Dumping in some water and agitating seems to stop development fairly quickly. Also film developing times are usually quite a bit longer than paper development times, so by the time you get to the stop bath nothing much is happening anyway.
     
  10. Emile, I develop by inspection usually 2 or 3 12x20 at the time and use water as a stop bath, since pyro oxidizes readily once the print is placed in water I beleive the developing action is stopped. I have seen no problem or bad effects doing this, so I am sticiking with it.
     
  11. Emile, last year, without fanfare, Ilford discontinued their IN-1 acetic acid indicator stop bath. They replaced it with Ilfostop, a citric acid, odorless, indicator stop bath. They also make Ilfostop Pro stop bath that has no indicator dye but contains some acetic acid. For a while, Ilford did not recommend the use of a stop bath with film. However, they now recommend using the Ilfopro stop bath with film. Two reasons: first, it stops the developing process very rapidly. Second, it helps to prevent the fixer from becoming exausted. If you are using PMK, or any pyro developer. Use a water stop and an alkaline fixer to maintain the tanning stain. If you are using a developer that contains a carbonate accelerator, a strong acetic acid stop bath may form gasses that could cause pinholes. Steve Anchell has an interesting discussion on this subject in his book "The Film Developing Cookbook". Not using a stop bath for printing will rapidly exaust the fixer and run the risk of streaking and staining. Ilfostop is a pleasure to use in open print trays compared to acetic acid stop bath.
     
  12. I switched to water after using for a long time indicator stop bath
    , and a quick try to the odorless which was making me cough
    all the time .
    It would tingle my throat .
    MMMMh, what about No pulp , unsweetened lemonade ?
     
  13. Emile,

    I'm new to LF but not to roll film. Does anyone know why odorless stop bath is odorless? If the active ingredients are the same but, something has been added to disguise the smell then, you are not doing yourself any favors by using it. Just because something is odorless does not meean it is safe.

    Stop bath seems to work for a very, very long time. I always throw it out long before it shows signs of exhaustion. About a year ago, I started to mix it at half the recommended dilution without any apparent changes to my negatives.


    Just my 2 cents...

    Ray C.
     
  14. I use water with film but stop bath for prints. Sprint has an
    odorless stop bath, and fixer too. http://sprintsystems.com. A
    small company based here in little Rhody. (Rhode Island USA).
     
  15. The side effect of using water instead of stop bath is developer (alkaline)carrying over into the fixer (acid) and shortening the fixer's life.
     
  16. Good day! I've got a 1952 edition of "The Theory of the Photographic Process" by Mees and it has a section on factors affecting grain. They note the two main contibutors are sudden temperature change and extreem pH change. Stop bath has two main purposes, to arrest developer action and preserve the fixer solution from developer carry-over. If you desire very precise development time control, a stop bath will assure it. It is my practice to use a stop bath with tight temperature control. I've had very good results from this approach. I like lots of fresh air exchange too!
     
  17. Vinegar is acetic acid, and lemon juice contains both ascorbic and citric acid.

    I suppose you could use lemon juice instead of vinegar in your developing process. I wonder if it would stain the negative ... hmmmm .... maybe there is a clear lemon juice, or crushed vitamin-C tablets (ascorbic acid) could be used.

    I am currently using a Yankee 12-film tank for development, and I use water as a stop bath. I do a couple of water changes before I put in the fixer, and the fixer seems to be holding up just fine.
     
  18. I use a water bath and an alkaline fixer. An added attraction of the water bath is that you can also use it for presoak (obviously freshening it before each batch), for films that do better with a presoak.

    I can see more of a case for stop with development by inspection, where you might want to use the stop bath as a holding bath while you wait for all the negs to develop to satisfaction, then transfer the whole batch to the fixer at once.
     
  19. There is nothing like a shot of GOB (Good Old Brandy). It works best with a shot just before developing, a shot to arrest it, and than another one immediately after the fixer. After an hour-long darkroom sesion you're always happy with the results, no matter what they are.
     
  20. To hell with stop bath. Use water for prints and film. Toss your old acid fixer and get some alkaline fixer. It'll eliminate your worries about killing your acid fixer with an alkaline developer. You'll get to really like the mild ammonia smell. Mmmmmm....ammonia.
     
  21. The stop bath is 1. the barrier between the alkaline developer and the
    alkaline labile fixer and 2. a time point to clearly stop the developing process.

    1. If you cary some basic developer solution (high pH) into the fixer solution
    (usually sodium thiosulfate) then the pH of the fixer solution becomes also
    high (gets more basic) and begins to decompose itself (becomes turbid; that's
    sulfur...a product of this chemical decomposition of a thiosulfate). This
    problem can be solved in two ways: Either you use a stop bath which is
    simply an acid or you use a different kind of fixer which is stable under high
    (basic) conditions. In the past one has used acetic acid (vinegar) as a cheap
    "non poisonous" but noxious acid for the stop bath in order to neutralize the
    base of the developer and therefore to lower the pH of the solution sticking to
    the negative/print. Acetic acid (vinegar) stinks; it is volatile. This is about the
    same stupidity as using lead in gasoline. In the case of acetic acid one can
    easily replace it with any other mild, cheap and non-poisonous non-volatile
    acid like citric acid. Acetic acid gives off vapours which your lung does not
    apreciate and which are in fact very unhealthy. You dont want to expose your
    loung to acid, do you! Citric acid is not volatile and is a solid at room
    temperature, so use citric acid but for shure not acetic acid anymore.

    2. If you dump an emulsion which is saturated with developer into a water
    bath, then the developing process continues for a while until it is diluted to
    such an extent that its effect of developing can be neglected. Dilution
    processes in an emulsion are not very fast so "diluting-out" is a bit tricky.
    However, todays film (but not print!) emulsions are so thin that the developer
    is pretty quickly diluted out of the emulsion with water. However if you want to
    have a clear stop-point for every developing process, then use a stop bath.
     
  22. Thanks a bunch for all the info!
     

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