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  1. #21

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    Rotary processing with any pyrogallol based developer. with or without presoaking, is risky. I say this in spite of the fact that quite a number of people make beautiful negatives with developers like PMK and Rollo Pyro in Jobo, tubes, and drums. In spite of their success the reports of failures due to irregular staining, rib marks, marks on the back of the film, etc. are numerous.

    I used PMK for many years as my main developer of large format sheet film, with tray processing. However, when I started to use PMK with rotary processing, in BTZS tubes and print drums, I experienced many of the problems mentioned above. These failures were one of the primary reasons I developed the Pyrocat-HD formula, based on pyrocatechin (or pyrocatechol). In my opinion there is no question but that pyrocatechin is a much better reducer (cleaner working and less tendency to irregular and uneven staining) for use in rotary type development than pyrogallol, and I am sure that many who have compared Pyrocat-HD in this application to staining developers based on pyrogallol would agree.

    Some information on Pyrocat-HD is at ://unblinkingeye.com/.

    Sandy King

  2. #22
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  3. #23

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    Hi Aggie,

    PMK is a fine developer and I used it extensively over a period of many years. I have absolutely nothing negative to say about it as a general purpose developer. For silver gelatin printing, with development in tray, tanks, or via nitrogen burst system, it is at or near the top of my list.

    However, rotary processing has many advantage, not the least of which is the fact that it gives the most even development of any system. Also, rotary develoment in Jobo, tubes or drums uses very small quantities of developer, making it very economical, and it has a very small footprint, especially for very large sheet film, say over 8X10. Just think, for example, of the difference in space requirments for developing a sheet of 8X20 film in trays, as opposed to developing the same sheet in a print drum. Big saving in both space and amount of developer.

    Finally, both Rollo Pyro and Pyrocat-HD make a lot more sense for alternative printers than PMK, whatever your sytem of development, because of time considerations. For example, to develop a negative taken under normal SBR conditions (SBR 7) to proper CI for printing with AZO or an alternative process (Pt/Pd, carbon, kallitye) PMK requires about twenty minutes of development, compared to about eight for both Rollo Pyro and Pyrocat-HD. With low contrast scenes the situation is even more tilted against PMK.

    Sandy King


  4. #24
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  5. #25

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    Aggie,


    What you describe apears to be the result of what is called infectious development, caused by halation or the scattering of light in the film emulsion. You typically see this in the shadow areas adjacent to extreme highlights. All staining developers, including PMK and Pyrocat-HD, tan and harden the gelatin, and minimize this effect. Assuming your original negative was developed in PMK I don't believe another staining developer would do much better.


    It may also be that the negative was simply developed for too long. This would accentuate the bleed over of density from the highlights into the shadows.

    Sandy

  6. #26
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  7. #27

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    When you have a really high contrast scene, like the one Aggie is describing you can get highlight bleed when using a staining developer. I first noticed this when scanning some 6x9cm negatives. Cutting back on the development time and agitation helped but never completely eliminated the effect.

    With high contrast scenes I have had better success with compensating developers, and D-23 works well with most films I use (TMAX and APX100). I dilute D-23 1:1 and develop for around 10 minutes followed by a 4 minute bath in either Kodalk or Borax. 20 Mule Train Borax from my local supermarket works just great and can be had for a great price.

    Mike

  8. #28
    Ole
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    Aggie, you have halation. Even the best anti-halation coatings aren't perfect, just like the anti-reflex coatings on lenses. This is a fact of life, and no developer is going to get rid of it.

    Sandy, halation and infectous development are completely unrelated phenomena. One is optical, the other is chemical. Infectious development is normally only seen with the (extreme) high-contrast developers known as lith developers. If other developers show infectious development, they shouldn't be used.

    For a nice example of halation, look at the woodland negatives in Les McLean's book...
    -- Ole Tjugen, Luddite Elitist
    Norway

  9. #29
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  10. #30
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    Aggie give Pyrocat-HD a try. I have used it in tanks as well as tubes and it has done a great job. I saw no difference in development between the two systems. Since I don't have a Unicolor or Jobo system I use hangers.
    www.ericrose.com
    yourbaddog.com

    "civility is not a sign of weakness" JFK

    "The Dude abides" - the Dude

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