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Thread: Divided Procat HD

  1. #11
    おせわに なります! Andrew O'Neill's Avatar
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    Re: Divided Procat HD

    Hi Walterb,

    Try the same test again but this time use a tray. I'm getting nice, smooth skies.

  2. #12

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    Re: Divided Procat HD

    Quote Originally Posted by Ken Lee View Post
    In Solution A, there is no development of course, so there's nothing to see. I see the blotches in Solution B.

    In my case, the blotches run vertically along the edges of the photos. When I get some time, I will post some proofs.

    Over the weekend, I can run a test and look more carefully if that will help.
    Yes, I am very interested in determining exactly when the blotches begin. If it is an uneven draining issue adding a bit of wetting agent to Solution A might solve the problem.

    Sandy
    For discussion and information about carbon transfer please visit the carbon group at groups.io
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  3. #13

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    Re: Divided Procat HD

    I develop Arista APHS Ortho film much the way Ken develops his film; in a tray, by inspection (although, there's not much to inspect with 2-bath development; one second there's no image, the next there is). I find APHS to be very sensitive to handling, so I process in a single tray, beginning with water for the pre-soak. I dump out the pre-soak water, with the backing dyes, and pour in the A solution, with vigorous agitation throughout the absorption time. The film is completely clear during this phase. I pour out the A solution, and as quickly as I can, I pour in the B solution, again with vigorous agitation. The image pops up in a few seconds, but I develop for a full minute. I pour out the B solution and rinse the film with clean water, changing twice. Then I pour in the fix. The fixer I use fixes APHS almost instantly, but I fix for a full minute. I pour out the fixer and wash in clean water, add a few drops of photoflo at the end of the wash cycle, clip the film clip on the corner of the film and pull it out of the tray to hang dry.

    I know this is a tedious process, but this film is so sensitive to handling, it's the only way I can get pristine negatives. If any film was going to streak or blotch, it would be this stuff. If I had problems with uneven development, I would use brush agitation (cheap sponge paintbrush, in my case).

    Ken,

    Edge density is sometimes associated with using too small a tray for the format being developed. What size trays are you using?

  4. #14

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    Re: Divided Procat HD



    Here is a sample image from a run I did 5 days ago. It is a proof of the shot. No adjustment has been made to contrast, or anything else for that matter.

    At that time, I was taking all my sheets from A, and putting them into B all at once - and only then, starting to shuffle.

    As you can see, the blotches are mainly along the edges, but not exclusively.

    After seeing those blotches, I developed another batch a few days later. That time, I made sure to immerse each negative into B separately and completely - instead of immersing them all at once. Below is a photo from that batch. Because there was no obvious blotching, I could edit the file in Photoshop, adjust the contrast, and make a real photo from it.



    I may be wrong, but it appears that development happens the moment the film enters B, so it's imperative that it be uniform. The negative has to be fully submerged, all at the same time. I wonder if it might make sense to use B at a higher dilution, IE a weaker solution, so that development not be so sudden.
    Last edited by Ken Lee; 5-Sep-2018 at 16:52.

  5. #15

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    Re: Divided Procat HD

    Quote Originally Posted by Ken Lee View Post

    I may be wrong, but it appears that development happens the moment the film enters B, so it's imperative that it be uniform. The negative has to be fully submerged, all at the same time. I wonder if it might make sense to use B at a higher dilution, IE a weaker solution, so that development not be so sudden.
    It is also very important in stand development, where we use very dilute solutions, that the negative be wetted out with the developer uniformly, and as quickly as possible, and then agitated vigorously for at least one full minute afterward. Failure to do so will result in uneven development not unlike what is being described in this thread.

    From what I have read so far it seems that uniform and quick immersion of the negative in Solution B may be the solution. I will run some tests when I get some spare time but based on earlier calibration I am fairly certain that it will not be possible to use a weaker dilution of Solution B. But I will test to make sure.

    Sandy
    For discussion and information about carbon transfer please visit the carbon group at groups.io
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  6. #16

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    Re: Divided Procat HD

    If I look at Walters first neg very carefully the streaks seems to exhibit a very faint adjacency effect along both edges of the streaks. I have noticed this using Diafine in tray development and ascribed it to streaks of solution A being left on the film while plunging it into solution B. Maybe these streaks inhibit the initial action of solution B in an, albeit small, but detectable way. That comment on the very fast development of the image at the start of solution B may suggest that the non uniform streaks of A are exaggerated by B.

    The notion of a touch of wetting agent in A is interesting. I should try that with Diafine.

    BTW Sandy, many thanks for your nice writeup on Diafine a couple of years ago in View Camera magazine. It prompted me to get busy and work on the technique of two bath development.

    Nate Potter, Austin TX.

  7. #17

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    Re: Divided Procat HD

    Sandy,

    I don't mean to butt in, and I don't know how you tested to arrive at your optimum dilution of your B bath, but a less alkaline B bath at a higher concentration might provide smoother, less blotch-prone development. If Nathan is on to something, it could mean the very same factors that produce sharpness are responsible for the blotching.

  8. #18

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    Re: Divided Procat HD

    I have taken the liberty of adding the following to the instructions page on Divided Pyrocat HD.

    "Negatives must be fully immersed in Solution B and agitated vigorously for at least one full minute. Failure to do so, can result in uneven development."

  9. #19

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    Re: Divided Procat HD

    Andrew
    I can't use trays as I don't have a darkroom. Load the film in the JoBo in a closet and development is on the kitchen counter .

    I plan to test again later today using a small amount of wetting agent in A as Sandy has suggested. Will post my results when finished.

    Would it make sense to give a quick clear water rinse after the A solution?
    Also is it at all possible that the dye released from the pre-soak could be a factor?

    Thanks to all I appreciate the help.

  10. #20

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    Re: Divided Procat HD

    Quote Originally Posted by walterb View Post
    Andrew
    I can't use trays as I don't have a darkroom. Load the film in the JoBo in a closet and development is on the kitchen counter .

    I plan to test again later today using a small amount of wetting agent in A as Sandy has suggested. Will post my results when finished.

    Would it make sense to give a quick clear water rinse after the A solution?
    Also is it at all possible that the dye released from the pre-soak could be a factor?

    Thanks to all I appreciate the help.
    Walter,

    You should not rinse the film with water after the A solution. This would wash out the reducer which must be in the emulsion of the film when you transfer it to Solution B. If you rinse most of the reducer will be removed and you will get virtually no development.

    The wetting agent may help, and I would suggest increasing the amount of Solution A and B. My suspicion is that for some reason the solution flow in your Jobo does not allow the film to be wet completely out all at once and perhaps using more solution wil remedy this.

    I have not seen any mottling in my use of Pyrocat-HD but my system of development of sheet film, which is in print drums or BTZS tubes, assures that the film is wet out immediately in all of the solutions. I really believe this is the key to even development.

    Sandy
    For discussion and information about carbon transfer please visit the carbon group at groups.io
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