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  1. #21
    Mark Burley's Avatar
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    Good luck with the film trials Stoo. You should have asked me re where to stay in Portwrinkle. I would have given you a few addresses.

    As for scary waves, I got very wet taking the shots in Portwrinkle. Worst one being chest height. I honestly thought I was going to lose the Blad and tripod - brown trousers/shorts was the order of the day. I just caught the tripod as it lifted off the rocks. After that I realised I had pushed it too far. I found it very difficult to judge when to retreat back up to the beach. Leave to early and lose out on great shots or risk soaking everything but get at least a shot or two in the bag. Either way I got thoroughly soaked every day for a week.

    I would do it again tomorrow though - what a fantastic venue... As for Porth Nanven - I'm jealous, not got there yet.
    It has to be one of the most interesting challenges in Cornwall. By the way, have you seen Andrew Nadolski's book - The End of Land. That's based on Porth Nanven. Wonderful colour neg based images (he uses Reala and Velvia I think)

    Mark

  2. #22
    Stoo Batchelor's Avatar
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    Quote Originally Posted by dancqu View Post
    Thornton's A of two baths. Likely the 80 grams of sulfite.

    Headache? I'll explain. Two bath developers, Diafine,
    divided D23, Stockler's, etc, all have developing agent
    and alkali, activator, in A bath. A thorough soaking of the
    emulsion and shorted development there then to the B bath
    for continued development in that alkaline solution.

    The developing agent within the emulsion is depleted
    rapidly as it tackles the more exposed areas. The less
    exposed areas continue to develop depleting the carry
    forward developing agent only slowly. Of course the
    developer is washed and diffuses from the emulsion.
    Two or three minutes in B I'd think about it. Dan
    Dan, thanks for taking time out to explain but the headache continues!

    Heres why:

    D-23 chemical make up ~ 7.5 gram Metol
    100 gram Sodium Suplhite
    Water

    Stoeckler 'A' Bath ~ 5 gram Metol
    100 gram Sodium Sulphite
    Water

    Thorntons 'A' Bath ~ 6.5 gram Metol
    80 gram Sodium Sulphite
    Water.

    Now, I am assuming that By using the D23 alone, development would result in good negatives, assuming they were correctly exposed. But in Barry Thorntons book 'Edge of Darkness' he states, and I quote:

    "Bath 'A' contains only the developing agent and preservative. The second, bath 'B' contains the alkali activator and any restrainer"

    So, if that is the case, what is in the D-23 to activate the Metol? because Barry continues:

    "The exposed film is first immersed in tank or dish, in Bath 'A'. Because there is no activator present virtually no development takes place"

    O.k, I can see that there is more Metol in the D-23 than both Stoeckler and Thorntons formulas, but there is a lack of activator, hense the continuation of the development process is in need of a 'B' Bath , the activator, to yield a final correctly developed negative..

    You see why I am confused!

    How the bloody hell does the D-23 work? Beats the hell out of me!

    Mark, thanks for pointing me in the direction of the photographer Andrew Nadolski. I looked him up. Some of his work can be found here:

    http://www.tristansgallery.com/showGallery/21/245

    The trip to Porth Nanven was well worth the extra miles. Very special. I am afraid that I did not come away from Portwrinkle with much as a sea fog moved in while I was there. If you ever go to Porth Nanven, ask how to get there as it is not the easiest place to find, even with an O.S in your lap.

    Cheers Dan and Mark

    Best

    Stoo
    Last edited by Stoo Batchelor; 01-31-2008 at 02:56 PM. Click to view previous post history.
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  3. #23

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    Quote Originally Posted by Stoo Batchelor View Post
    Dan, thanks for taking time out to explain but the headache continues!

    "Bath 'A' contains only the developing agent and preservative.
    The second, bath 'B' contains the alkali activator and any restrainer"


    So, if that is the case, what is in the D-23 to activate the Metol?
    because Barry continues:

    "The exposed film is first immersed in tank or dish, in Bath 'A'.
    Because there is no activator present virtually no development
    takes place
    "

    Stoo
    Yet more headache! D-76H. Only 2.5 grams of metol. Barry, I'm
    sorry to say, has lead you into a state of confusion. Very simple.
    Sodium sulfite is both preservative AND ACTIVATOR. In fact
    sodium sulfite has a fairly high ph, round about 10. That is
    higher than borax or bicarbonate.

    So, metol and sodium sulfite in any reasonable proportion and
    the correct amount of water will develope film, even paper.

    It just so happens that Steve Anchell has addressed this issue
    of development in the A bath of the above and other two bath
    developers. In an article in Camera & Darkroom some years ago
    he modified a few formulas so to include sodium bisulfite.
    By so doing a lower ph and less A bath development.

    For greater development control the A bath can be inactive.
    Multiple passes twixt A and B baths are necessary. Dan

  4. #24
    Stoo Batchelor's Avatar
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    Quote Originally Posted by dancqu View Post
    Yet more headache! D-76H. Only 2.5 grams of metol. Barry, I'm
    sorry to say, has lead you into a state of confusion. Very simple.
    Sodium sulfite is both preservative AND ACTIVATOR. In fact
    sodium sulfite has a fairly high ph, round about 10. That is
    higher than borax or bicarbonate.

    So, metol and sodium sulfite in any reasonable proportion and
    the correct amount of water will develope film, even paper.

    It just so happens that Steve Anchell has addressed this issue
    of development in the A bath of the above and other two bath
    developers. In an article in Camera & Darkroom some years ago
    he modified a few formulas so to include sodium bisulfite.
    By so doing a lower ph and less A bath development.

    For greater development control the A bath can be inactive.
    Multiple passes twixt A and B baths are necessary. Dan
    Actually Dan, no. no more headache. You have explained it perfectly well, and I couldn't thank you enough.

    So the 'B' Bath, as Barry goes on to explain, is a final tweeking of what allready has taken place in bath 'A' And depending on what strength it is, will depend on the final contrast of the negative. Very interesting.

    Thanks Dan

    Best

    Stoo
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  5. #25

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    pH with sulfite

    There has been more misunderstanding, lies, faith, and confusion about two bath/divided developers than the death of JFK.

    Divided D-23 is the daddy of them all and seems to be Diafine (look at the MSDS.) D-23 has only the SS content to provide activation. Divided D-23 starts out as regular D-23 and as such, development does take place, but not a lot in 3 minutes. As you may know, you can extend the A development to change the film characteristics. The completion in Bath B is almost instantaneous, the 3 minutes is just for simplicity and marketing. However, it does provide a lot of "seed" sites for the sodium carbonate kick in the B bath.

    Some extensive notes of mine from the early 90's has pH vs. SS concentration. To be honest, I can't remember if I got this info elsewhere, or it was the result of my own tests. Anyway:

    30g/L of SS has a pH of about 8+
    60g/L of SS has a pH of about 9

    So, at 80-100 grams typical of most fine grain developers, you can expect a pH in the "low 9's." That's right there with D-76, +/- pH 9.2 - 9.5), which is right there with 10g/L of borax alone: pH 9.5.

    In the next week I will be trying a two bath developer that I got from the original article on from a Shutterbug in 1992, by Otha Spencer. He claims "no grain" on a Plus-X, 35mm to 11x14. If you have an eye for such things, it's a concentrated DK-50 with the sulfite held about the same.

    Metol, 6.5 g
    SS, 32.5 g
    HQ, 6.5 g
    Pot. Bromide, 3 g
    Water to make 1 Qt.

    I think that there is an error on the B bath, stating "3 oz, 200 grains." That's about 91 grams! Even undiluted Dektol/D-72 doesn't use that much. You can't go too far wrong at at 5 grams, est. pH of 11.6. Or maybe 10 g Kodalk (sodium metaborate) for a pH of 10.5. With a two bath, you can try any accelerator in any amount as you wish, they are cheap chemicals.

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