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  1. #1
    jp80874's Avatar
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    Jobo edge density film problem

    I am getting overdevelopment or high edge density on the film edge opposite the notch. This is the 7 inch side of 7x17 film. The other three edges are fine. Can you offer suggestions how to eliminate this problem?

    I am using 7x17 HP5+ film, Rollo Pyro developer from Bostick & Sullivan. I develop two sheets at a time of the same image bracketed 2 stops. The notched edge is always loaded at the top or lid end of either of two 2800 series drums. Emulsion faces to the center of the tank. The problem happens in either drum. I have ten film holders and the problem exists which ever film holder I use so I doubt it is a light leak. The higher density is roughly ¼ inch to 3/16ths”. Some times I can burn it out in printing with approximately 100% burning time or twice what it takes for the rest of the print.

    I have been using Rollo Pyro for at least five years, but this seems to be a recent problem.

    I am using a Jobo CPP-2 serial # 13391. I use a five minute prewash with the sodium metabolite that comes in the Rollo Pyro kit. This is ¼ teaspoon in 500 ml water. The water is 70 degrees F or 21.1 C. Development time is 6 minutes. In an experiment to reduce agitation I have been decreasing the rotation speed from 4, to 3, to F to the first notch beyond F. This seems to have made the problem worse.

    Any help appreciated. Ask if you have questions.

    Thanks,

    John Powers
    "If you want to be famous, you must do something more badly than anybody in the entire world." Miroslav Tichı

  2. #2
    Photo Engineer's Avatar
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    Jobo's newletter says to use the high speed setting on agitation. I also use a prewet and a stop bath.

    PE

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    Quote Originally Posted by Photo Engineer View Post
    Jobo's newletter says to use the high speed setting on agitation. I also use a prewet and a stop bath.

    PE

    Thank you PE.

    How high a speed number setting) does it suggest? I gather the speeds are different in different serial number ranges.

    Isn't this a prewash? "I use a five minute prewash with the sodium metabolite that comes in the Rollo Pyro kit. This is ¼ teaspoon in 500 ml water."

    As a stop bath the Rollo Pyro directions suggest two quick dumps of the 750ml each of water before the fixer. I do this. Are you suggesting something else?

    Thank you for your help.

    John
    "If you want to be famous, you must do something more badly than anybody in the entire world." Miroslav Tichı

  4. #4
    Photo Engineer's Avatar
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    Well, a prewet in most cases is just water, but with this version of Pyro you have to go with what they say as a prewet. As for agitation, it does vary from machine to machine. I have 2 and use 2 different settings.

    A stop is a stop. This is generally 1% - 2% Acetic Acid and nothing more. It promotes uniformity, especially with LF films and drum processors.

    And the shorter the development times, the worse the uniformity anyhow.

    PE

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    Quote Originally Posted by Photo Engineer View Post
    And the shorter the development times, the worse the uniformity anyhow.

    PE
    If I lowered the temperature to 68F and increased the time would this accomplish what you are suggesting, or do I need a greater change?

    The rest of the image looks great at 70F and 6 minutes. I don't want to mess that up.

    Thank you.


    John
    "If you want to be famous, you must do something more badly than anybody in the entire world." Miroslav Tichı

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    Using 68F is more normal IMHO. You can't go too wrong. But, I am unfamiliar with Rollo Pyro.

    PE

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    This post


    provides all you need to know about Jobo rotation speeds.

    You have two potential issues. First, 2800 series are paper drums, not intended for use with film. The old Jobo distributor in Michigan used to make and sell special inserts that were intended to overcome the problems inherent in that misapplication. Many have reported successfully processing sheet film in these drums, but almost always when not using a staining developer.

    Since you appear to have been doing this trouble-free in the past, it's possible something about the film or developer has changed. I recall Sandy King posting that, despite Jobo's above-linked recommendation for a setting that results in 45-50 rpm when processing film, he always uses the slowest rotation speed possible. Hopefully Sandy will chime in with further insight.

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    Have you tried processing one sheet of film in a tray to rule out possible camera / holder issues? Or load the film with the notch at the bottom of the tank?

  9. #9
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    wow Sal, I completely missed the "paper drum" issue. That could be a significant factor here. As you note, the internal design is different for film drums.

    PE

  10. #10
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    Thank you all. As mentioned this did work well for several years and only recently, 3-6 months, has it gotten bad. Slowing rotation down has made the problem worse. I am planning to go back to setting 4 where I started and gradually try increasing speed. I will try to count rpm but it is two way rotation and counting my be hard. I do like the idea of centering the film away from the bottom. Certainly no reason not to try it notch down.

    I have very bad allergies and went to the Jobo to avoid fumes. I have powerful exhaust and filtered input fans in a 10x13x7 foot darkroom. I used nitril gloves and a 3m filtered mask from B&S. Metol and ammonia seem to be the worst for the allergies. I have switched to a non ammonia fix for paper in trays, but I use Ilford Hypan in the Jobo. Rollo Pyro starts with a metol wash and has more in the developer, so for me it has to stay in the Jobo.

    Thank you for your ideas. I will be off line until tomorrow afternoon Eastern US time, but will respond to any additional ideas then.

    Thanks,

    John
    "If you want to be famous, you must do something more badly than anybody in the entire world." Miroslav Tichı

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