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  1. #1

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    I have been reading the Edge of Darkness by Barry Thornton and I really like the idea of two bath developing but I dont quite understand it.

    How exactly do you do this? I am a little confused on the chemicals that is needed. But I like that fact that it really holds backthe highlihght and when shooting 120 or 35 it gives you better development.

    One day I will switch to 4x5 but for now I need to find the best way to develop my negatives and it seems the two bath is the way to go but I need help in understanding it.

    Thanks,

    Kev

  2. #2
    Leon's Avatar
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    there are many two bath developer formulae, you can find some in the Darkroom Cookbook ) and other books. Barry Thornton has a better description of 2 bath techniques on his website http://www.barry-thornton.co.uk/2bath.htm

    I find that 2 bath developing can be tricky, and any slight impurity in the water or other contaminants can cause uneven negs and other unwanted effects. My answer was to try a tanning/staining formula for their compensatory effects - pyrocat hd is superb, but Barry Thornton's DiXactol (in the one bath option) and Exactol Lux are also pretty good too.

    good luck!

  3. #3
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    Quote Originally Posted by kjsphoto
    I have been reading the Edge of Darkness by Barry Thornton and I really like the idea of two bath developing but I dont quite understand it.
    With respect to the Stöckler developer where Barry started I recommend the follwoing article: http://www.largeformatphotography.info/twobath/
    He demonstrates that with formulas like Stöckler or Barry's two bath or divided D-23, where there is sufficient alkalinity present because of sulfite-content developement of hidlights and midtones is determined by the time spent in bath A alone. I found this to be true as I developed a test-film in Bath A only. Shadows were weaker, midtones and higlights were the same as usual.

    As Barry Thorntons formula is a refinement of the stöckler-formula you can expect it to behave in more or less same way except some more contrast at the same time/temperature. This is at least how they compared in my hands. The stöckler is a bit more fine grained but Barry's formula keeps its promise of very good definiton. It is definitely worth a try.

    Stefan

  4. #4

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    Kevin,

    I assume you are asking about 120 roll fim development.

    Which B&W film(s) are you planning to use? Will silver bromide enlargements be your end product?
    Tom Hoskinson
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  5. #5
    Joe Lipka's Avatar
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    Don't get the idea that two bath development is just for sheet film. You can use a two bath developer with roll film, too.
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  6. #6

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    Hello Tom,

    Yes 120 and maybe the occasional 35mm but not very often. For 120 It will be TMAX 100, Delta 400, Neopan 100.

    For now because of where I live I will have to scan all the negs. I have an high end drum scanner but I want to preserve the detail in both the highlight and shadow areas. If there is a better technique than the 2 stop then I am all ears. I use A12 backs and will usually shoot in the same light per roll. I also sometimes bracket. I also use my 6x17 which give me 4 shots on the roll of 120. With this camera I want to have better control. I usually only take 2 shots per roll as I bracket each shot because if the filter I have to use to give is even lighting. A center filter.

    Thanks again and I am open to all suggestions. I usually just used the film at it said speed. But after reading it seem that if I set 100 to 50 on a contrast day then subtract from development time it should yield a better negative with better sharpness. At least according to the book if I read it right. The end prints are prints to at least 24+ inches. The panoramic images are 30-60" wide. I will either print out on an Epson 7600 or send them out to have them printed.

    As soon as we move I will build a darkroom so I need to have the best negative that I can get now so when I can get back in a darkroom I will have nice negatives to work with.

    Thanks,

    Kev

  7. #7

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    No worries.

    I have used two bath developers for both roll and sheet film - when some advantage could be gained - usually I have not found it advantageous. However, in some instances it can be advantageous.

    The emulsion type and end usage can be important to developer choice. Whether the emulsion is coated on roll film or sheet film is of secondary importance. However, some emulsions are only available for certain specific film sizes.

    Barry Thornton (Edge of Darkness) migrated from split (Stoeckler type) developers to single solution developers. His reasons for migrating can be found on his website.
    Tom Hoskinson
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  8. #8

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    Kevin, the developer I personally use with all three of these films is Sandy King's Pyrocat-HD. This developer is available as A & B liquid concentrates from Bostick & Sullivan. I mix my own "from scratch."

    I usually develop to maximum densities that are compatible with Azo contact printing, unless my goal is a projection enlargement. I scan all my roll film (up to 6x9cm) at 400dpi with my Nikon Super Coolscan 8000. I scan my 6x12's and 4x5's with a Microtek 6800 at 4000dpi and contact print on Azo. I make proof prints on a HP 7960.

    I have not tried Kodak Xtol or any of the other Ascorbic Acid/Phenidone based developers (I have the chemistry, but have not found the time). They are reputed to work well with the films you listed. The Ascorbic Acid/Phenidone developers also have very low human and environmental toxicity.
    Tom Hoskinson
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  9. #9

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    I am scanning on a Imacon from 35mm up to 6x17. I have been shooting a lot of BW lately. I am kind of bored with color and do not know if I will go back to it. BW just has more feeling and depth.

    What is the best method to retain both Highlight and shadow without either blocking up. If 2 bath is not necessary that is ok as well. I just do not know. Also do you shoot the film at the listed speed or set it based on light condition then underdevelop?

    Thanks again,

    Kev

  10. #10

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    Kevin, start by reading and re-reading your Barry Thornton book.

    It is important to do enough testing such that you can understand and predict how your camera, lens, film and developing process will respond to the range of light in a given scene.

    Get into the habit of measuring and recording the maximum and minimum brightness of the scenes you photograph. Look for the APUG threads on this subject for "how to's."

    You need to test your film/developer combinations in order to determine how the combinations respond to light and thus, how they record shadow and highlight detail.

    Once you have learned how your system reacts to light, meter and expose to record the important shadow details in the scene.

    Some films are capable of recording much wider scene brightness ranges than others. Examples include Kodak Tri-X, Ilford FP4, Efke 100 and J&C Classic 400.

    Most of the characteristics of a film are put there by the film manufacturer. However, highly dilute staining and tanning developers like Pyrocat-HD provide compensating development, and also proportionally tan and stain the highlight areas in the emulsion, which helps prevent the highlight areas from "blowing out." In the highlight areas the emulsion tans and hardens quickly, this causes a localized slow down in development. At the same time, the shadows will fully develop, providing full film speed.

    Explore the film/developer threads on APUG and the Azo Forum, they are loaded with good "how to" information on this subject.
    Tom Hoskinson
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