Fuji Acros in Pyrocat-HD

Discussion in 'B&W: Film, Paper, Chemistry' started by sanking, Feb 9, 2008.

  1. sanking

    sanking Member

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    Below is some BTZS data derived from testing Fuji Across, 120 size, in Pyrocat-HD with what I call extreme minimal agitation.

    For those not familiar with Fuji Acros it is a very fine grain, very high resolution medium speed film, of ASA 100. When used with a high quality medium format 6X7 or 6X9 camera and lens, and exposed on a tripod, this combination is capable of results equal to, or in some cases superior, to 4X5 LF when using higher speed films.

    The Pyrocat-HD dilution was 1:1:100, with development at 70F. The film was agitated vigorously for one one minute at the beginning of development, then for ten seconds at the one-quarter, one-half and three-quarter points of development. No pre-soak was used. The stop was 1/2 strength acetic acid, fixer was Formulary TF-4.


    When the step wedge negatives were processed and dried they were read with a densitometer (Blue Mode) and the curves were plotted with WinPlotter. The EF (exposure scale) in WinPlotter was set to 1.40, which should give good results with VC silver gelatin papers. For scanning I would recommend reducing development times by about 15%.

    Results below.

    SBR Time
    9 11 minutes
    10 14 minutes
    11 20 minutes
    12 29 minutes

    TIME Average Gradient (Approximate CI)
    10 0.5
    12 0.55
    14 0.60
    16 0.65
    20 0.70
    24 0.75
    26 0.80
    30 0.85

    The tests indicate that the EFS (effective film speed) of Acros is about 115 with this developer and type of agitation, and is virtually the same from SBR 9 through SBR 6 so no change of development is indicated for Plus or Minus develoment within these limits.

    Sandy King
     
    Last edited by a moderator: Feb 9, 2008
  2. keithwms

    keithwms Member

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    Wow thanks Sandy, very powerful info.
     
  3. sanking

    sanking Member

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    Hi Keith,

    Thanks. Give the combination a try. You will find it very hard to beat for making prints up to 18X22 or 18X24 from 6X7 and 6X9 negatives. At this size the prints should be very sharp and have a nice tight grain pattern.

    I find the Acros just slightly better than Tmax-100. Acros grain is finer, sharpness about the same.

    Sandy
     
  4. malinmalin

    malinmalin Member

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    I'll sure give it a try soon!
    Sandy, what was the dev time you used?

    jf
     
  5. sanking

    sanking Member

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    I used several development times in order to plot the data. What you need to do is match the subject brightness of the scene and develop for the time indicated. If, for example, you are developing for printing on VC silver papers, use SBR of 7 (N) and the time indicated. If your scene is very low contrast, use an SBR of 6 and develop for the time indicated. If the scene is high contrast, use an SBR of 8 or 9 and develop for the time indicated.

    Sandy
     
  6. malinmalin

    malinmalin Member

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    I should read before replying!
    Need some more coffee :smile:

    Thank you!
    jf
     
  7. Buster6X6

    Buster6X6 Member

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    Thanks Sandy
    It is my film of choice for 6X6 and 6X9. Would the data be the same for Pyrocat-MC which I use primarily. Thanks in advance.

    Greg
     
  8. sanking

    sanking Member

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    Yes, in developing -MC I adjusted the formula to give development times that are almost the same as for -HD.

    Sandy
     
  9. Buster6X6

    Buster6X6 Member

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    Thank you Sandy.I have been using this combination for over a year now and it is great.

    Greg
     
  10. Peter Schrager

    Peter Schrager Subscriber

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    fuji and pyrocat mc

    sandy-been using this combo for quite some time now except no minimal agitation...have made some of my best prints to date along with graded paper...
    always a thanks for your thorough work.
    Best, Peter
     
  11. pgomena

    pgomena Member

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    Sandy, I'm confused. You list developing times for SBR 9 through 12, but times for shorter SBRs (5 through 8). Am I missing something here?

    Peter Gomena

    P.S. I agree that this is a great film/developer combination. The tonality is really smooth. Thanks for the test results!
     
  12. sanking

    sanking Member

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    Hi Peter,

    Thank you very much for pointing this out. Somehow the data was totally garbled. I think this happened when I edited the message to correct a typo. Here is the true SBR data.

    SBR -----Time of Development in Minutes
    10 ----- 9 minutes
    9 -----12 minutes
    8 -----14 minutes
    7 -----20 minutes
    6 -----29 minutes

    Sandy
     
    Last edited by a moderator: Feb 9, 2008
  13. Dave Swinnard

    Dave Swinnard Subscriber

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    Hi Sandy

    Perfect timing... I've just started testing Acros roll film with Pyrocat HD and minimal agitation.

    I just wanted to clarify - you indicated no pre-soak was used. Have you changed your mind about pre-soaking for minimal agitation with roll film and Pyrocat? (last year you recommended 5 minutes for stand and minimal ag. situations.)

    Dave
     
  14. sanking

    sanking Member

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    I still recommend the pre-soak, though I believe two minutes is enough for minimal agitation. However, when all development times are ten minutes or longer the pre-soak is not necessary for testing since it will have very little impact on contrast.

    With any type of minimal agitation it is very important that the first minute of agitation be quite vigorous and as random as possible.

    Sandy
     
  15. Rick Olson

    Rick Olson Member

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    Sandy,

    I tried some Acros today with my 6x7 (but used Pyrocat-MC) using the details above for SBR 7. Stunning results!

    Thanks,
    Rick
     
  16. sanking

    sanking Member

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    Hi Rick,

    I have been using Acros with both -HD and -MC for about six months with MF 6X7 and 6X9 and am really pleased with the fine grain and sharpness. However, I had actually never tested it with BTZS and thought this would be interesting to add more precision to my work.

    What I like about Acros, in addition to the very fine grain and very high resolution is the fact that, 1) reciprocity failure is very low, which means that in low light conditions exposures might actually be shorter than with a high speed film like HP4+, and 2) EFS is fairly constant over a wide range of SBR conditions.

    Good luck with your work with this film, and thanks for the report.

    Sandy
     
  17. onnect17

    onnect17 Member

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    Hi Sandy,

    Why should I reduce the development times for scanning?

    Thanks,
    Armando
     
  18. eddie gunks

    eddie gunks Member

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    it is early so sorry if i am not getting it but is the second chart the chart to use? seems that they are opposite each other.

    i plan to use this film for my pinhole cameras as the reciprocity is excellent! what would you say i should use for printing on VC papers? thanks again.

    eddie

    ps. i have just began mixing HD from bulk chemicals. so far so good. this is fun!
     
  19. Baxter Bradford

    Baxter Bradford Member

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    Have you by any chance similar figures for developing Acros/Pyrocat HD in a Jobo processor please Sandy? I'd love to be able to tweak my timings. Currently it all gets 10 min 15s on the fast rotation speed of 75rpm.

    Many thanks
     
  20. Alden

    Alden Member

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    Mr. King. I hope you'll forgive me if this is too much of a tangent, but as I see and have known about your comprehensiveness with data, I'm going to ask that slippery question. Why pyro? I worked successfully for two years with four different pyros, primarily pyrocat, then even Illumitol from a New Zealander's formula. I never had a problem matching those results with D-76, if I did a side by side photograph regardless of the brightness range, using VC papers.

    Ultimately I found the pyro highlights were a little flat compared to 76, and ultimately as a fellow once said on rec.darkroom, "it's just a matter of whether you like creamy highlights or crisp ones". To develop for snappier highlight with pyro would seem to defeat the purpose completely.

    So is there data to suggest you are getting more tones to the paper, or something else I'm not considering, or does this interest in pyro remain inexplicable and a subjective artistic choice? I'm hoping for more than a "whatever works for you" response, again because your interest in data seems so complete.