Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,707   Posts: 1,548,544   Online: 1124
      
Page 5 of 5 FirstFirst 12345
Results 41 to 49 of 49

Thread: Pyrocat-HD

  1. #41
    Eric Rose's Avatar
    Join Date
    Nov 2002
    Location
    Calgary AB, Canada
    Shooter
    4x5 Format
    Posts
    4,259
    Images
    73
    Now for something not so technical. I just developed a roll of TX 320 using a half filled bottle of solutions A and B that had been sitting there for at least a year. Mixed them up 1.5:1.5:100 and dev for 15min's. Guess what? They turned out beautiful! I had previously developed it's sister roll in HC110 dil B and the PyroCat HD negs look and print much better. Mind you it was one of those sweeping prairie landscapes with lots of puffy clouds that PC-HD seems to love.

    Just thought I would throw this in as it seems everyone thinks the shelf life is pretty limited.
    www.ericrose.com
    yourbaddog.com

    "civility is not a sign of weakness" JFK

    "The Dude abides" - the Dude

  2. #42

    Join Date
    Mar 2003
    Location
    Greenville, SC
    Shooter
    Large Format
    Posts
    4,813
    Images
    5
    Quote Originally Posted by EricR
    Now for something not so technical. I just developed a roll of TX 320 using a half filled bottle of solutions A and B that had been sitting there for at least a year. Mixed them up 1.5:1.5:100 and dev for 15min's. Guess what? They turned out beautiful! I had previously developed it's sister roll in HC110 dil B and the PyroCat HD negs look and print much better. Mind you it was one of those sweeping prairie landscapes with lots of puffy clouds that PC-HD seems to love.

    Just thought I would throw this in as it seems everyone thinks the shelf life is pretty limited.
    Eric,

    I am really glad that you posted this information. When I originally introduced the Pyrocat-HD formula I was very conservative in the estimated stability of the stock solutions because at the time I had only about six months of experience in working with the final formula. So I gave an estimated shell life of 1/2 of that time, i.e. three months, to be on the safe side. And the original formula was for only 100ml of Stock A and B solutions, as some might recall, in the e anticipation that most users would need to mix again in three months or less.

    Now that several years have passed, and I have had a lot of experience with the keeping qualities of the stock solutions, I know for a fact that the shell life in partially full bottles (assuming mixing with distilled water) is at least two years, and perhaps even more. But I have been reluctant to state this fact without verification from actual work in the field by others. So for the reality check I thank you.


    Sandy King

  3. #43

    Join Date
    Sep 2002
    Shooter
    Large Format
    Posts
    4,530
    Quote Originally Posted by sanking

    To balance the mixture at 1:1:100 I figure to adjust the Stock B Sodium Hyroxide solution to about 12%. Does that sound about right to you. I notice that your working solution is 1:1.5:100 with a 10% Stock B sodium hydroxide solution, which sounds very close to what I came up with as the best mix of the two stock solutions.

    Sandy
    Sounds about right, I guess if you do the 12% solution you would need a 1:1:100 concentration to get similar results as 2:2:100 when using carbonate accelerator. For simplicity sake I settled on 1:1:100 using NaOH 10% and giving a little bit more developing time to acheive the same CI. I think I mentioned this, but IMO this combinatin is not good for long scale negatives as the times get really short.

  4. #44

    Join Date
    Mar 2003
    Location
    Greenville, SC
    Shooter
    Large Format
    Posts
    4,813
    Images
    5
    [quote="Jorge"]
    Quote Originally Posted by sanking

    For simplicity sake I settled on 1:1:100 using NaOH 10% and giving a little bit more developing time to acheive the same CI. I think I mentioned this, but IMO this combinatin is not good for long scale negatives as the times get really short.
    Yes, that is obvious from my tests. But bear in mind that I am looking for a specific solution with these tests, i.e. how to get enought contrast from low contrast films like BPF, JandC Classic, HP5+, and even 320TXP when used in low contrast lighting and intended for printing with alternative processes. You must have a developer with a lot of energy to get past the relatively low Gamma Infinity range of these films with standard strength developers. Even the regular 2:2:100 dilution of Pyrocat-HD, which is a very energetic developer by most standards, comes up a bit short with these films in these situations.

    Just looking at the data suggests that a 2:2:100 working dilution of Pyrocat-HD using a 10-12% sodium hydroxide Stock B solution in place of the regular 75% potassium carbonate Stock B will solve the problem.

    I think this is an important consideration because in my experience a very large part of ULF work is done for alterntive printing, with low contrast films in low contrast lighting.



    Sandy [/i]

  5. #45

    Join Date
    Sep 2002
    Shooter
    Large Format
    Posts
    4,530
    I agree, for increasing contrast the sodium hydroxide activator is much better.

    BTW I tried the semi stand developing with NaOH and I would not recommend it for this technique. The negative still printed beautifully but it was bullet proof, with a 6.2 SBR and 45.8 min developing the neg had 3.11 for the white parts with detail and 2.42 density for the middle gray (UV), took 1000 units in the Nuarc to print..lol....still, sharpeness, skin tone and tonal transition were beautiful...the lady was very happy...

  6. #46

    Join Date
    Dec 2002
    Shooter
    Large Format
    Posts
    6,242
    Quote Originally Posted by Jorge
    I agree, for increasing contrast the sodium hydroxide activator is much better.

    BTW I tried the semi stand developing with NaOH and I would not recommend it for this technique. The negative still printed beautifully but it was bullet proof, with a 6.2 SBR and 45.8 min developing the neg had 3.11 for the white parts with detail and 2.42 density for the middle gray (UV), took 1000 units in the Nuarc to print..lol....still, sharpeness, skin tone and tonal transition were beautiful...the lady was very happy...:)
    Jorge,

    What was your shadow density on the neg?

  7. #47

    Join Date
    Sep 2002
    Shooter
    Large Format
    Posts
    4,530
    Shadow with detail was 1.49, and "zone I" was .84 all in UV readings.

  8. #48

    Join Date
    Dec 2002
    Shooter
    Large Format
    Posts
    6,242
    Jorge,

    Thanks for the information.

    Donald Miller

  9. #49

    Join Date
    Feb 2003
    Location
    Norwich, UK
    Shooter
    Multi Format
    Posts
    1,405
    Images
    90
    Quote Originally Posted by Jorge
    ... took 1000 units in the Nuarc to print..lol....
    Careful Jorge, you might cause another North American blackout

    Phill Dresser
    It is not tradition that secures the survival of our craft, its the craft that secures the survival of our traditions.

Page 5 of 5 FirstFirst 12345


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin