Roll Film AGITATION - Thornton's Two Bath

Discussion in 'B&W: Film, Paper, Chemistry' started by Shawn Dougherty, Aug 19, 2013.

  1. Shawn Dougherty

    Shawn Dougherty Subscriber

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    I have been working with Thorton's Two Bath Developer (120 roll film on stainless reels) for the past couple of months. I have had excellent luck so far and am settling into an agitation pattern. I have The Edge of Darkness and have done quite a bit of "web" reading on this developer.

    I am especially curious about how others are agitating their roll film on stainless reels. This seems to be where the biggest variances occur.

    Also, I have been experimenting with Barry's N+ recommendation of a bath B using 20g of Sodium Metaborate instead of the normal 12g. (I have not yet needed an N- that the normal processing didn't handle). When using these variations, are you sticking with your normal agitation or changing that as well?

    Thanks for your input.
     
  2. Thomas Bertilsson

    Thomas Bertilsson Subscriber

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    Shawn,

    Just out of curiosity, what differences do you see at N development when you change agitation?

    Thanks.
     
  3. Shawn Dougherty

    Shawn Dougherty Subscriber

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    I suppose since I am asking others to share their agitation schemes and thoughts for Thorton's Two Bath the least I could do is write out and share how I am currently doing things.

    I set up a 1 liter measuring cup almost filled with distilled water and one drop of LFN wetting agent - Bath A solution is in a two (120) reel tank filled just over halfway (600ml) - Bath B solution is in a two reel tank filled just over halfway (600ml) - a 1 liter measuring cup filled with tap water for a quick water stop - then another 1 liter measuring cup with fixer.

    My film is loaded on a Hewes reel with a stainless lifting rod, processing one roll at a time. I pre-soak for 2 minutes and let drip for 30 seconds.

    I then start Bath A with 1 minute of agitation. Agitation is done by lifting the rod up so the top of the reel meets the top of the tank and then setting it back down. After 3 up and downs I rotate the tank a few degrees. After the first minute I repeat with 3 up and down motions every 30seconds followed each time by another slight rotation of the tank.

    I let it drip for 15 seconds.

    I then start Bath B with 15 seconds of agitation. Agitation is done in the same style as Bath A except that I agitate only at the top of each minute instead of every 30 seconds.

    I let it drip for 15 seconds and then 15 seconds in the water stop with agitation the entire time, again by lifting the reel out of the solution and setting it back in.

    From there I go into the fixer.

    I plan to do some testing with less agitation in bath A (and using a bath B with less Sodium Metaborate) for more extreme N- situations but have not yet done so.
     
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  4. Shawn Dougherty

    Shawn Dougherty Subscriber

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    Thomas,
    I have seen the biggest difference in the highlights when I agitate more or less in Bath A. Very little change seems to occur when I agitate more or less in Bath B.

    Of course this is to be expected, Thornton's being more of an afterbath type of developer than a true two bath developer (a true two bath developer being one in which almost all of the development takes place in the second bath.)

    This is why I am planning on testing the N- version (7g of Sodium Metaborate in Bath B instead of 12g) with reduced agitation in bath A as well. Maybe once a minute instead of every 30s. Of course I will work through those variables one at a time.

    -------------------
    So far I have found I get nice, very printable results with my N process from a moderate N+ through a moderate N- scene. (I should add that I have been bracketing one way. An exposure at what I think is best and then an exposure one stop below that. I was doing a third exposure one stop above metered at first but found that was never the exposure that printed best. I should also add that I tend to expose generously in the first place.)
     
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  5. Michael R 1974

    Michael R 1974 Subscriber

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    I was hoping to do some testing on this but just haven't had enough time lately. But here are some initial thoughts.

    I'm not entirely convinced by Thornton's line of reasoning regarding changing contrast by altering the amount of alkali in bath B (ie altering pH). Of course, what we need to know first is if development in bath B is to exhaustion with the N formula and time. Typically with two-bath/divided baths development is assumed to be carried out to exhaustion in bath B. Suppose this is the case. Then suppose the only thing you change vs. the N-process is to increase the Metaborate concentration to 20g/L. It seems to me all this would do is increase the rate of development in bath B. Why would it increase contrast? You've still got the same amount of bath A absorbed in the emulsion as in the N process, which places a finite limit on the amount of reduction which can take place in bath B. So from a tonality perspective wouldn't you just get the same result, only faster? The only mechanism I can think of which might lead to a small increase in contrast with more Metaborate (or a decrease in contrast with less Metaborate) is the relative resistance to the decreased pH associated with the buildup of acidic development by-products. Perhaps that is what is happening. Not sure if the effect is significant as Metaborate is a somewhat buffered alkali.

    The conventional way of altering contrast with this sort of developer (ie where there is activity in bath A) is to simply alter the time and/or agitation in bath A. At least on the surface of things, this seems like the most logical approach to me. I also think it would be the least risky from a uniformity perspective (for increases in contrast), and should be the most consistent from an image structure perspective. Increasing the pH of bath B can only make it harder to achieve uniformity as development in bath B is fast. The many threads/discussions with Sandy King regarding divided Pyrocat allude to this issue. Regarding image structure, varying the pH of bath B can also affect graininess - even if there is no change in contrast. Not that graininess is bad, and in medium/large format it might be invisible anyway. Just asking the question.

    I suppose the best thing would be to try what Thornton says and see if it works as expected.

    One thing that surprised me in your description is the use of a pre-soak.

    Can't really comment on the agitation technique per se since I've never tried it. But what you're doing with the separate tanks is a good idea particularly for bath B. Pouring/dumping would definitely increase the probability of getting unevenness in bath B where development is rapid. If you're getting even development, stick with what you're doing.
     
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  6. Shawn Dougherty

    Shawn Dougherty Subscriber

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    Michael,
    What you're saying makes sense to me. I have definitely determined that I can affect the density of the highlights through normal time / agitation changes in Bath A. (So far I have kept the times for Bath A and Bath B the same for simplicity sake.)

    I have only processed two rolls of N+ thus far. With the first roll, all I changed was the amount of Sodium Metaborate in Bath B. I did not see much of a contrast increase over what I metered. No prints yet, but the highlight densities are not what I would normally expect from N+ development.

    With the second roll I increased the Sodium Metaborate AND increased the development time by 1 minute. This roll looked like a normal N roll, so there was a definite increase in the highlight density from what my meter showed.

    This would seem to support you theory. (Though I do not have a densitometer I believe I have enough experience to judge whether or not there was an increase in the highlight densities based on how I metered the scenes, at least with a non-staining negative.)

    For my next N+ roll I plan to use the the normal amount of Sodium Metaborate in bath B and simply increase the time by 1 minute. If that works, the next time I feel I need a lot of expansion I will not only increase the time by one minute but agitate more frequently as well.

    When next I encounter a scene which requires serious N- development I will try decreasing the time, and for the second roll decreasing the time as well as the agitation in Bath A.

    I will say that there does indeed seem to be some compensating effect in the normal procedure, as I mentioned I have exposed moderate N- scenes on the same roll as N scenes and moderate N+ scenes and come away with negatives that print more easily that when I did this with other developers (which happened frequently with my Rolleiflex T as there is no ability to change backs).

    -----------
    As far as the Pre-Soak...
    My main reason for doing a short presoak is to remove the AH dye. I have been running 8 rolls through 1 liter of Bath A (Thornton suggested 15 was possible so I thought I'd be conservative. It's pretty cheap stuff even at 8 rolls). 8 rolls worth of AH dye in the developer would be quite messy. I'm not sure if that would matter but it would certainly make it difficult for me to see if there were particles or foreign objects in the developer. I let the negatives drain off water for 30 seconds and shake them a bit during that time. Also, my N time for HP5+ has been 5 minutes so I assumed that in that amount of time there would be plenty of chemistry absorbed by the emulsion.
     
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  7. Gerald C Koch

    Gerald C Koch Member

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    I consider the inventors of Diafine to be the experts on two bath developers. Baumann was the company that did the research and popularized this development method. They recommend 5s of gentle agitation initially and then 5s every minute. They warn that too vigorous agitation will result in loss of shadow detail. Two bath developers are all variations on a theme and they are more similar than they are different. Development is a diffusion controlled process and too much agitation will only cause problems.
     
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  8. Shawn Dougherty

    Shawn Dougherty Subscriber

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    Gerald,
    Could you elaborate a bit? 5s initially and then 5s every minute... Does that apply to both Bath A as well as Bath B?
    Thank you.
     
  9. mrred

    mrred Subscriber

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    I really don't see the point with agitation when using thornton. To maximise edge effects, less is more. It is like the perfect stand developer; the stuff is not in the soup long enough to get the normal bad effects from stand. Yes, I do give a 30 second fierce shake ending with a firm tap to lodge the air bubbles. But that is it.

    Here is an example of Orwo UN54

    8674494395_ee557a661e_b_d.jpg

    I also realize there will be many that can't let go of the agitation, but the results are fantastic.

    A nice side effect of this is the dev times get closer together, thus harder to screw up.
     
  10. Shawn Dougherty

    Shawn Dougherty Subscriber

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    The point of agitation is to control development thus affecting tonality in a predictable way.

    For me personally, well, my negatives are plenty sharp, I'm not looking for edge effects. I'm only making contact prints so even if they weren't very sharp they would be sharp enough. I've had enough experience with stand development to realize it is not for me. Reduced agitation to help control an extremely high contrast scene is one thing. I just don't believe stand development is a good general purpose development method.

    Even Gerald's suggestion of only 5 seconds of initial agitation makes me a little nervous. =)
     
  11. mrred

    mrred Subscriber

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    It works for me well enough that I have two bags of xtol that will likely never get mixed.
     
  12. Jeff Bannow

    Jeff Bannow Member

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    I'm doing one slow inversion every 30 seconds for A and one slow inversion every minute for B, no presoak.

    I'm using 2x 120 reels (both loaded with 120) in a stainless steel tank designed for 2x 120 reels. I'm placing a 35mm reel on top as a spacer so the reels don't move around in the tank too much.
     
  13. David Allen

    David Allen Member

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    Firstly, I do not use metal tanks - so this should be taken into consideration - but have exclusively used Barry Thornton's two-bath developer with 120 Delta 400 film for many many years.

    The processing sequence that works for me (using Paterson plastic tanks) is as follows:

    00:00 pre-soak with constant agitation
    01:45 drain pre-soak out of the tank
    02:00 Pour Bath A in and invert 4 times in the first 30 seconds followed by a sharp tap on the bottom of the tank to dislodge any possible air bubbles. Then one gentle inversion every 30 seconds always followed by a sharp tap on the bottom of the tank to dislodge any possible air bubbles.
    06:45 Pour Bath A out of tank into a jug.
    07:00 Pour Bath B in and invert 4 times in the first 30 seconds followed by a sharp tap on the bottom of the tank to dislodge any possible air bubbles. Then one gentle inversion every 30 seconds always followed by a sharp tap on the bottom of the tank to dislodge any possible air bubbles.
    11:45 Pour Bath B out of tank into a jug.
    12:00 Pour in water stop bath and agitate constantly
    12:45 Pour water stop bath out into the drain.
    13:00 Pour in fix and agitate constantly
    15:00 Remove films from tank and place into a large jug of water and leave until all of the pink dye is removed from the film then return the film to the fix for a further 2 minutes.
    Finally, wash using the Ilford method.

    A note on mixing the chemicals and use
    • I mix up 1 litre of Bath A (my tank is the 1 litre version that can accommodate up to 4 films) and store in a 1 litre dark brown glass bottle. This one litre is sufficient for 24 films (but note the following point about Bath B).
    • I mix up two litres of Bath B at the normal 12g of Sodium Metaborate (which are stored in two 1 litre dark brown glass bottles) and use each bottle of Bath B for 12 films and then discard.
    • I mix up one litre of Bath B at the N+ dilution of 20g of Sodium Metaborate (which is stored in a 1 litre dark brown glass bottles) and use rarely when needed.

    A note on the N-, N and N+ dilutions
    • 99% of all my photographs are developed with the N version of Bath B. I have never had any negative where I felt that it should have been developed using the N- version of Bath B.
    • The N+ version of Bath B is useful but not in the sense of a strict +1 stop expansion (which can be much better achieved by selenium toning the negative). If I photograph something that has dark shadows and bright highlights but also a significant part of the scene is relatively lacking in mid-tone separation then I use the N+ version of Bath B. This has a significant effect on expanding the mid-tones of a scene that was lacking such a mid-tone separation.

    Having just quickly looked through the 100 odd images on my website, there are 6 photographs where I used the N+ Bath B and all of the rest were developed using the normal Bath B.

    Best of luck finding your own best way of using Thornton's two-bath developer - it is a great, reliable and cheap developer.

    Bests,

    David
    www.dsallen.de
     
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  15. Shawn Dougherty

    Shawn Dougherty Subscriber

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    Jeff and David,
    Thank you both very much for your input. I appreciate it!

    I wonder if either of you could let me know the process by which you arrived at your agitation procedures? Did you hit any bumps or make any interesting observations along the way?

    Thanks again, fellows. =)
     
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  16. ed1k

    ed1k Member

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    I use original Stoeckler's formula and I do not agitate much. Neither I pre-soak film (my understanding is emulsion should be soaked with bath A solution). Yes, I do initial agitation and tap to rid off bubbles, then little agitation once every 2-3 minutes if I remember and near by. Same with bath B. To control contrast I do change developing time in bath A; the more you develop in A the more contrast you get.
     
  17. Gerald C Koch

    Gerald C Koch Member

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    Sorry I had intended to mention that it applies to both baths. With this !@#$% editor it's lucky that anything gets posted.

    Baumann published a nice 4 page instruction booklet on their developers which gave detailed instructions on agitation.

    Jerry
     
  18. Jeff Bannow

    Jeff Bannow Member

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    No problem! I went off of Barry Thornton's writings on the process mostly. I use my tank setup because that's what I've always used, since I was taught in college.
     
  19. Shawn Dougherty

    Shawn Dougherty Subscriber

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    Gerald,
    Nevermind, I searched and found an official Diafine PDF with the recommendations you mention. Thanks again for pointing that out.
     
  20. Shawn Dougherty

    Shawn Dougherty Subscriber

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    Gerald,
    We must have been posting at the same time! =) I found that booklet this morning. Thanks again!

    I may do a test with those procedures and compare them them to what I've been doing. That is significantly less agitation than I have been using, especially for that first minute in Bath A.


    Thank you, Jeff!
     
  21. Shawn Dougherty

    Shawn Dougherty Subscriber

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    Thank you for that. Could you elaborate a bit on exactly HOW you agitate? I'm especially interested in that because it seems (so far in my limited testing) that agitation makes as big a difference in the highlights as the amount of time in Bath A.
     
  22. Shawn Dougherty

    Shawn Dougherty Subscriber

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    I just read this in the Diafine PDF:

    "Because Diafine is a true two-bath developer, each film type is developed to a fixed degree of contrast, and changes in the developing times will have no practical effect on the final results."

    This is different than Thornton's Two Bath (not a true two bath), where times definitely have an effect on the final results. I'm now wondering how much the agitation recommendations for Diafine relate to Thornton's given the differences.

    At this point I'm thinking limited agitation in Bath B (5 seconds every minute and let the shadow development do it's thing (this is basically what I have been doing except I was using 15 seconds initial agitation)). And stick to changes in agitation (and time) using Bath A where you have real control over the highlight density.

    Thanks again to everyone for contributing thus far.
     
  23. ed1k

    ed1k Member

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    Normally I agitate by inverting tank, that is by turning tank up side down and back. Applicable to plastic tank which takes only one 120 film reel and to SS two reels tank (If I develop one film I use empty reel so lower reel with film don't move far). Usually I use plastic tank for two bath development; however I didn't notice any difference in result.
     
  24. Shawn Dougherty

    Shawn Dougherty Subscriber

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    Thank you!
     
  25. David Allen

    David Allen Member

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    When I do tests (which, these days, is only when a film or paper is changed | discontinued) my goal has always been to limit as many variables as possible and to be clear what I am trying to achieve.

    What I want from a film | developer combination is unobtrusive grain, reasonably high acutance and good tonality.

    When testing a film | developer combination there are a number of things that never vary:

    All chemicals are always at 20˚ C.
    Processing commences with a two minute pre-soak.
    Agitation is always pour in the developer and gently invert the tank 4 times during the first 30 seconds followed by a sharp tap on the bottom of the tank to dislodge any possible air bubbles. Then one gentle inversion every 30 seconds always followed by a sharp tap on the bottom of the tank to dislodge any possible air bubbles.

    By keeping all of these variables fixed I can then concentrate on finding the correct development time.

    With Delta 400 rated at a personal Exposure Index of 200 I found that 5 minutes in each bath of Barry Thornton's two-bath developer gave me a full range of tones with good shadow detail and equally good detail in the highlights. My first tests at 4 minutes produced acceptable negatives that I felt were just a bit on the soft side. Times longer than 5 minutes produced no noticeable benefit as far as what I require.

    Bests,

    David
    www.dsallen.de
     
  26. Shawn Dougherty

    Shawn Dougherty Subscriber

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    Thank you very much, David. I appreciate the time you've taken to spell all of this out for me.
     
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