Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,871   Posts: 1,583,399   Online: 1110
      
Page 1 of 2 12 LastLast
Results 1 to 10 of 14
  1. #1
    noseoil's Avatar
    Join Date
    Oct 2003
    Location
    Tucson
    Shooter
    Multi Format
    Posts
    2,898
    Images
    17

    Pyrocat dilutions

    Ive been using pyrocat-hd for a couple of years now and have found it to be a great developer with good versatility, tonality, grain and generally fine results. My normal solution is 1:1:150 for most things, with the occasional semi-stand thrown in for good measure. It seems capable of decent results with many different films, traditional to tabular.

    I continue to hear about people who have "tweaked" the numbers by varying the concentration with respect to parts A & B. For example, some folks use it with 1: 1.5: 150 or 1.5 : 1: 200. I know that changing dilution and agitation can affect development and grain, but could someone explain how this change in dilution of the A & B parts affects development? Does it change the actual film's curve at all, or does it simply change development time?

    Thanks, a befuddled tim

    P.S. I'm interested in people who have actually done these experiments, not in the cousin of a step-brother whose milkman knew a guy whose uncle was working in....

  2. #2

    Join Date
    Jan 2003
    Location
    NW Chicagoland
    Shooter
    Multi Format
    Posts
    577
    Images
    1
    Tim,
    Hate to throw your question back at you but how did you end up with 1:1:150 instead of the "standard" 1:1:100?

  3. #3
    noseoil's Avatar
    Join Date
    Oct 2003
    Location
    Tucson
    Shooter
    Multi Format
    Posts
    2,898
    Images
    17
    Chuck, I use minimal agitation as this slows things down a bit. It really helps when doing films like Efke 25, which reacts too quickly for me with the standard dilution, almost a violent development. Since I liked the results, I've started doing more with it and other films. Efke 100 gives good results with nice edges and a bit faster film speed. It seems that minimal agitation allows the film to develop fully and slowly. Perhaps not for everyone, as it does take more time in the soup, but as an amateur, there isn't a problem for me and longer development times. best, tim

  4. #4
    c6h6o3's Avatar
    Join Date
    Oct 2002
    Shooter
    Large Format
    Posts
    3,194
    Images
    6
    Quote Originally Posted by noseoil View Post

    I continue to hear about people who have "tweaked" the numbers by varying the concentration with respect to parts A & B. For example, some folks use it with 1: 1.5: 150 or 1.5 : 1: 200.
    I use a dilution of 1:0.6:120 or 1:0.6:150 using semi-stand development on the advice of Steve Sherman when I need extreme compensation (approx. N-5 development). Backing off on the B solution, which is the accelerator, reduces highlight development while allowing the shadows to develop fully.

    For normal negatives to be developed semi-stand I'll use 1:1:120.

  5. #5
    Shawn Dougherty's Avatar
    Join Date
    Jul 2004
    Location
    Pennsylvania
    Shooter
    Multi Format
    Posts
    4,141
    Images
    298
    I use 2:2:150 for my Delta 100 negs to print on graded paper. 1:1:100 negs were too thin, 2:2:100 negs seemed too dense.... 2:2:150 negs print just right. I have little to no understanding of what why or how, just that they look good.

  6. #6
    Thomas Bertilsson's Avatar
    Join Date
    Jan 2003
    Location
    Minnesota
    Shooter
    Multi Format
    Posts
    14,559
    Images
    300
    I think part A contains the normal developing agents, and part B is the 'activator'. I think you want to focus on varying the part B for various results. More of it should accelerate your development if I understand it correctly.
    I use 1+1+100 for my Tri-X, Foma 400, and some Agfa APX films at 16 minutes with reduced agitation (once every 3 minutes). For FP4+ I dilute more to 1+1+150 but keep the time constant. It works very well for me, and I have found no reason to experiment with it more.
    To vary the relationship between part A and part B to other than 50/50 - I have no experience. I think you need enough of part A to make sure you don't exhaust the developer, and enough of part B to accelerate the development to your liking.
    Someone with more profound knowledge will have to confirm this, however, as I am not generally interested in the scientific part of it.

    - Thomas
    "Often moments come looking for us". - Robert Frank

    "Make good art!" - Neil Gaiman

    "...the heart and mind are the true lens of the camera". - Yousuf Karsh

  7. #7
    climbabout's Avatar
    Join Date
    Aug 2005
    Location
    Fairfield County CT
    Shooter
    8x10 Format
    Posts
    225

    pyrocat dilution

    Tim -
    I arrived at 1.5/1/175 as my standard dilution. I

    can't tell you what it does to the curve, but I arrived at it by trial and error when I was fitting FP4+ to the paper I use. I mainly contact print on graded FB paper and this dilution gives me nicely developed highlights and full shadow detail. My normal development is what I guess you call extreme minimal or minimal agitation. Plus this gives me full(actually a little more than full) film speed. I rate my 8x10 fp4+ at 160, dilute at 1.5/1/175 and develop for 45min(70 degf) in a pvc tube - fully filled with solution. Agitate vigorously for the 1st minute, then 2 inversions at 15min, then 2 inversions at 30min. The tube stands on end between agitation cycles. I usually get a near perfect print at my standard proofing time with great edge contast on what is essentially a grade 2 paper. I develop the paper in DR. Beers at the #4 dilution - which allows me to vary the dilution both up or down in contrast up to 3/4 of a grade.
    I've compared negs of the same scene developed in a rotary jobo at a slow speed at 1:1:100 and the difference in edge contrast is remarkable. Altering the amount of restrainer (B) seems to keep the highlights where I like them. Sorry if I'm not more scientific - but I arrived at this based on what I see in the final print.
    I've simplified my life greatly by sticking to one film/one paper/and now 1 developer.

    Hope this helps.
    Tim

  8. #8
    Bruce Osgood's Avatar
    Join Date
    Sep 2002
    Location
    Brooklyn, N.Y. USA
    Shooter
    Multi Format
    Posts
    2,461
    Images
    47
    I come from the point of view that Pyrocat HD was developed for use in a Jobo/roller system and was intended for constant agitation.

    My Jobo has one speed only and I had disappointing results with 1:1:100. Sandy suggested I try 1.3:1:100 to compensate for the "High" speed of the single speed Jobo. I did and it seemed to work but not to what I expected.

    I now use 2.6:2:100 and get what I think are good negatives. My films are FP4+ and HP5+. "Normal" times are about 10:00 minutes and I do use a pre wash.

  9. #9

    Join Date
    Nov 2004
    Shooter
    Multi Format
    Posts
    2,068
    Tim, I use 2+2+100. I can't fully answer your question, but at 1+1+100 the negs were thin.

  10. #10

    Join Date
    Mar 2003
    Location
    Greenville, SC
    Shooter
    Large Format
    Posts
    4,813
    Images
    5
    Almost all developers, Pyrocat included, can be used with a wide variety of dilutions. My earliest recommendations were dilutions of 1:1:100 for silver papers and 2:2:100 for alternative processes, with either development in tray or tank with normal agitation, or development in Jobo or BTZS tubes with constant agitation. Development times given were based on rotary, so if developing in tanks and trays development should be increased by about 15-20%.

    Pyrocat also works well with stand and semi- stand development using very dilute solutions, say 1:1:200 - 400. As a result of a long exchange on the AZO forum, 1:1:150 was recommended for stand and semi-stand development. This requires much longer development time than either rotary or tray processing, both because of the weaker dilution and because of the reduced agitation.

    For most of my own work with both sheet film and roll film I personally use a type of development that I have called Extreme Minimal, that is, agitation for 1.5 minutes at the beginning, and then for ten seconds at the 1/4, 1/2 and 3/4 points of total development time. The dilution that I use is 1.5:1:200.
    The slight increase in the amount of A solution compared to 1:1:150 is meant to reduce B+F stain slightly with the very long development times I need for my alternative process negatives.

    Sandy Kiing

Page 1 of 2 12 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



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