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  1. #21

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    This is why I said he should do his own testing. My tests show that for my water etc, etc. TMY developed in Pyrocat (2:2:100) in Jobo expert drums at 20º C for an Average gradient of 0.83 had a b+f of 0.44. A target average gradient of 0.68 had a whoping 0.33 b+f. (all UV readings)

    This is clearly unacceptable, I cannot try and print pt/pd with b+f of 0.33. This adds one stop exposure to my printing times. This is why we do our own testing, no?

  2. #22

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    The Summitek Cradles (sloshers) are well made and reasonably priced. They are available for 4x5 and 5x7.

    http://www.summitek.com/cradle.html

    The PF sloshers are of equivalent quality to the Summitek Cradles, but at a higher price. PF does make an 8x10 version
    Tom Hoskinson
    ______________________________

    Everything is analog - even digital :D

  3. #23

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    Quote Originally Posted by Jorge
    This is why I said he should do his own testing. My tests show that for my water etc, etc. TMY developed in Pyrocat (2:2:100) in Jobo expert drums at 20º C for an Average gradient of 0.83 had a b+f of 0.44. A target average gradient of 0.68 had a whoping 0.33 b+f. (all UV readings)

    This is clearly unacceptable, I cannot try and print pt/pd with b+f of 0.33. This adds one stop exposure to my printing times. This is why we do our own testing, no?

    Yes, your B+F levels, even with the 2:2:100 dilution, are high in comparison to mine. The question is why? I don't think it has anything to do with water, since the potassium carbonate solution at 2:2:100 is extremely well buffered. I am guessing that the speed of rotation of your Jobo is much faster than I get with my method of rotary, which is about 5 RPM or slightly lower.

    I must confess that I have never directly compared Xtol to Pyrocat-HD, but my comparison to D76 1:1 for an average gradient of .83 shows a B+F of 0.13 with D76 versus 0.15 with Pyrocat-HD, 2:2:100.

    Sandy

  4. #24

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    Quote Originally Posted by sanking
    Yes, your B+F levels, even with the 2:2:100 dilution, are high in comparison to mine. The question is why? I don't think it has anything to do with water, since the potassium carbonate solution at 2:2:100 is extremely well buffered. I am guessing that the speed of rotation of your Jobo is much faster than I get with my method of rotary, which is about 5 RPM or slightly lower.

    I must confess that I have never directly compared Xtol to Pyrocat-HD, but my comparison to D76 1:1 for an average gradient of .83 shows a B+F of 0.13 with D76 versus 0.15 with Pyrocat-HD.

    Sandy
    I dont think it is speed rotation as much as time outside the developer. With brush development I had very little b+f, with the JandC drums it was the same thing, low b+f even at fast rotations, but with the Jobo, the film spends a lot of time out of the developer since the drums have a large diameter. I imagine if I increase the potasium bromide a little bit (maybe from 0.2 to 0.4) it might help, but I am almost sure it is due to aerial oxidation. Or I could do uniderctional developmet in the Jobo drum with faster speeds. I might try that another time and post it here, I have enough Xtol right now to last me for a few weeks, then again who knows, Kodak might decide to stop making and I am going to have to find a way to make Pyrocat work since I cannot get ilford here....

  5. #25

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    Quote Originally Posted by Jorge
    I dont think it is speed rotation as much as time outside the developer. With brush development I had very little b+f, with the JandC drums it was the same thing, low b+f even at fast rotations, but with the Jobo, the film spends a lot of time out of the developer since the drums have a large diameter. I imagine if I increase the potasium bromide a little bit (maybe from 0.2 to 0.4) it might help, but I am almost sure it is due to aerial oxidation. Or I could do uniderctional developmet in the Jobo drum with faster speeds. I might try that another time and post it here, I have enough Xtol right now to last me for a few weeks, then again who knows, Kodak might decide to stop making and I am going to have to find a way to make Pyrocat work since I cannot get ilford here....
    I would not recommend increasing the amount of bromide in the Pyrocat-HD solution as this will result in a loss of film speed. A much better solution in my opinion, based on your description of the problem, would be to add a small amount of ascorbic acid to the working dilution. Ascorbic acid, if added in the right amount, will cut B+F without a loss of film speed. But the amount needs to be just right because if you add too much you will kill the stain.

    For amount of ascorbic acid to add, I would suggest about 10 ml of a 1% ascorbic acid solution per liter of working Pyrocat-HD solution. This should drop B+F values without decreasing the stain.

    Sandy

  6. #26

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    Quote Originally Posted by sanking
    I would not recommend increasing the amount of bromide in the Pyrocat-HD solution as this will result in a loss of film speed. A much better solution in my opinion, based on your description of the problem, would be to add a small amount of ascorbic acid to the working dilution. Ascorbic acid, if added in the right amount, will cut B+F without a loss of film speed. But the amount needs to be just right because if you add too much you will kill the stain.

    For amount of ascorbic acid to add, I would suggest about 10 ml of a 1% ascorbic acid solution per liter of working Pyrocat-HD solution.

    Sandy
    Ah, I read you had done this. I thought the ascorbic acid was used to increase speed, so it also lowers b+f? I might just try that. Thanks!

  7. #27
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    This is the first time I've heard that development in trays will give good results with minimal agitation for edge effects (no problems with uneven staining as well, right). I had thought that tube development with a vertical orientation was necessary for proper development. Ah well, live and learn. Perhaps I shouldn't have made all of those 4x5 tubes and bought the 8x10 tubes from Mike, but I do enjoy working with the lights on as opposed to playing blind man's bluff in my blacked out bathroom...

    Using pyrocat in my normal dilution with trays is fine for minimal agitation, same times and temps? This would certainly save on both developer and distilled water. 8x10 tube development can get a bit spendy with distilled water and single sheets. With the water quality we have here (very hard) and the recharge of our aquifer with Colorado River water, I'm still reluctant to change what is working well.

    Minimal agitation with pyrocat and Efke 100 is the cat's a$$ for sharpness and tonality. Please don't tell me there's a better film for this next! tim

  8. #28

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    WHo said anything about minimal agitation? As I understand it, the question is what would give better and more even results, Jobo or Tray with Pyrocat? For minimal agitation there is only one way, tubes standing.

  9. #29
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    "Yes, I used to think that the negative had to be in vertical orientation with stand and semi-stand development, but the cradle concept with the negatives on the horizontal works great with this kind of development as I saw with Steve's negatives. Sandy"

    Jorge, this is what I was reacting to. tim

    P.S. Did you get a bit wet from Emily this week?

  10. #30

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    Quote Originally Posted by noseoil
    "Yes, I used to think that the negative had to be in vertical orientation with stand and semi-stand development, but the cradle concept with the negatives on the horizontal works great with this kind of development as I saw with Steve's negatives. Sandy"

    Jorge, this is what I was reacting to. tim

    P.S. Did you get a bit wet from Emily this week?
    Ah.....Nope, I live in the central part of Mexico, got a few rains but that is it... :-)

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