Pyrocat-HD: Uneven Negatives

Discussion in 'B&W: Film, Paper, Chemistry' started by boy scout, Jan 31, 2008.

  1. boy scout

    boy scout Guest

    Hi there! :smile:

    I just finished developing a roll of HP5+ using these specs:

    - 3:2:150 dilution
    - 68 degrees Fahrenheit
    - 11 minutes, first minute of continuous agitation, followed by 10 second inversions every minute.

    Doing so, I received uneven negatives. Some of my negatives seem to have more contrast than others.

    Gary Arnold has scans of his Pyro negs; his example mirrors that of my HP5+ results: http://www.garyarnold.com/tags/photography

    What could be the cause of uneven development?
     
  2. Ian Grant

    Ian Grant Subscriber

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    Well it's not the developer, here's no reason why Pyrocat should produce uneven development. I process my 5x4's and 120 the same way in Jobo & Paterson tanks using Pyrocat at 1+1+100 and inversion agitation.

    Your not clear what you mean by uneven, I assumed at first you meant marks from poor agitation, but looking at the link you posted maybe you mean the negative densities etc. In the link the negatives are quite clearly poorly exposed, so I guess your having similar problems.

    Pyrocat is an excellent developer, it maybe you neeed to look at your exposure/metering techniques.

    Ian
     
  3. noseoil

    noseoil Member

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    If "uneven" negatives and roll film means contrast in the prints, I would have to say that perhaps you exposed in differing light conditions. As Ian has suggested, there can be differences which the development doesn't allow for. As an example, in bright sunny conditions 11:00 may be correct, but in overcast or "flat light" in the shade, the 11:00 time may be too short to deal with the inherent low contrast in the scene. SBR or scene brightness range comes into play here. With sheet film, you can tailor development times to what is needed, but with roll film you need to develop for the "average" light in a scene, not always the best way to go in differing light conditions. tim
     
  4. juan

    juan Subscriber

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    Seems to me to be rather a strong dilution. 1:1:100 is more common for silver printing with standard agitation. The dilution you've used is more common for a minimal agitation scheme. Therefore, I'd say offhand that you've probably overdeveloped the negatives, leading to too much contrast. Maybe you've underexposed, too.
    juan
     
  5. gainer

    gainer Subscriber

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    3:2:150 is the same as 1.5:1.33:100. That should be MORE active than 1:1:100.
     
  6. Andrew Moxom

    Andrew Moxom Member

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    Did you do a pre soak? I did not see that in your process steps.... if the emulsion is not swelled up PRIOR to pyrocat dev, there could be problems.
     
  7. gainer

    gainer Subscriber

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    What I meant was that dilution would not be used for stand or minimum agitation. If you got the result right, it seems to have been for the wrong reason.
     
  8. boy scout

    boy scout Guest

    Thank you all for having thought of something important to say. :smile:

    Now that there is a). better lighting (daylight), and b) dry negatives - it turns out that the density for all my negatives are the same! Okay, well... about the same, as I bracketed exposures (200, 320 and 400) in diff. lighting situations.

    The dev. time was in fact too short for my given temp and dilution. I'm going to test clips today to figure out the proper times! I think I should be able to get it the second time around. :wink:
     
  9. matti

    matti Member

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    Remember that Pyrocat-HD negatives should look thinner due to transparent stain. So you might want to print something before you decide on times just by looking at the negatives.

    /matti