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  1. #141

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    Quote Originally Posted by Alan Johnson View Post
    I wonder if the humic acids produced by pyro developers harden the emulsion.This might result in slower diffusion of developer in highly exposed areas so that they do not burn out when printed.That's just a guess by the way,not to be quoted as fact.
    Pyro/Cat development tans (hardens) the emulsion. There is less silver developed and this is "made up for" by the stain which increases density proportionately with the amount of silver developed (ie the amount of exposure). This does not necessarily result in highlight compression in the negative, although there can be a compensation effect when printing on VC papers.

    One thing tanning does not do, is prevent silver migration, because silver does not migrate to begin with. That is a non issue with modern hardened films.

  2. #142
    Thomas Bertilsson's Avatar
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    No, Michael. Please don't turn it into that. I am not trying to destroy this thread about what developers are best and why.

    I find it important to understand the materials we use, and I'm not stopping you from exploring it. My goal is to try to present people, like the original poster of this thread, with a balanced approach of how to use and apply our materials. I'm trying to illustrate that technique and hard work will conquer materials every time, and that the original poster shouldn't be fooled into believing that using pyro will somehow magically transform his pictures from good to brilliant. I'm trying to keep that balance to a thread where someone is trying to find out what developer to use, and I'm illustrating how important it is to be consistent.

    So go on and discuss how pyrocatechin or pyrogallol and their respective types of stain will benefit your prints and how it happens, in this thread that was originally about finding out picking one developer over another, and I will sit here and be quiet about having a balanced approach to any materials we use.

    - Thomas

    Quote Originally Posted by Michael R 1974 View Post
    ...and yet another technical thread veers into speechmaking about learning to use our tools. Yes, yes, we all know this obvious truth regarding virtually any endeavor. It does not mean it is a waste of time to talk about the differences in materials when a question is posed. I especially think it is important since much of what is said is either incorrect or misleading.

    Yes it is true some of the differences between materials are immaterial, and should pobably be ignored. And yes how we refine our technique and work with our materials is extremely important. But there are sometimes characteristics which are quite different, not good or bad, but different, and there are implications when printing. Again, not good or bad, just characteristics worth understanding.

    For example, everybody talks about grain masking in Pyro negatives, how the stain makes grain less apparent. True, but the context is usually wrong. The grain masking effect reduces the prominence of grain relative to non-staining high acutance developers. Even with stain and less silver in them, Pyro and Cat negatives are still noticeably grainier, sometimes a lot grainier (depending on the formula) than a negative developed in XTOL. Sandy King himself has written about how if fine grain is important to someone using small or medium format they would probably be happier using XTOL than PMK or Pyrocat. The tiny differences, if any, in highlight tonality are outweighed, and can be compensated for with skill in printing.

    Just one example.
    "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

  3. #143
    Bob Carnie's Avatar
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    So you are saying the bare bulb in a room effect , one flared out* D76* , one crystal clear*Pyro* is a placebo effect and not real.

    I think I need an asprin, I have sold all this development based on this percieved effect.

    Quote Originally Posted by Michael R 1974 View Post
    Pyro/Cat development tans (hardens) the emulsion. There is less silver developed and this is "made up for" by the stain which increases density proportionately with the amount of silver developed (ie the amount of exposure). This does not necessarily result in highlight compression in the negative, although there can be a compensation effect when printing on VC papers.

    One thing tanning does not do, is prevent silver migration, because silver does not migrate to begin with. That is a non issue with modern hardened films.

  4. #144

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    Give me a break. The original question was whether one was better than the other. Discussing how they are different (not better or worse) can help someone make a more informed decision regarding which one to pick first (depending on what format they shoot etc), and then they can focus on mastering it with consistency, control and creativity. I'm not talking about debating microsopic differences, but simply being aware of basic, visible properties.

    I'm just saying that "pick something and learn to use it" should not be the default answer to technical questions. Otherwise we might as well have only one forum with an automated "learn to use it" response.

  5. #145

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    Quote Originally Posted by Bob Carnie View Post
    So you are saying the bare bulb in a room effect , one flared out* D76* , one crystal clear*Pyro* is a placebo effect and not real.

    I think I need an asprin, I have sold all this development based on this percieved effect.
    No no. I mean silver does not migrate. That's only one effect. There are still other things that enhance accutance and value discrimination in the tanned negative, like less halation and irradiation, and a lower probability of infectious development. I'm just suggesting people not go nuts thinking a stained negative will show massively different highlights than a well exposed/processed negative using a non-staining developer. I'd also add if exposure is heavy with Pyro/Cat, which several people on this thread have said they prefer, the enhancements pretty much go out the window. Sandy King has written alot about this stuff in other forums etc. For what it's worth I've done alot of my own experiments.

    I'm curious though about your flared-out D76 comment. Why does it have to be so? I agree there can be *slightly* more "bloom" around such objects with a sulfite developer than a staining developer, but the value differences and detail can be just as good, albeit harder to print in some cases. Can you explain?

  6. #146
    Thomas Bertilsson's Avatar
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    You have your opinion, and I have mine. Time to coexist. What you say, and what I say, can go hand in hand. In my mind they are not opposing views. Both rely on an importance of understanding the materials we use.
    You told me I shouldn't comment like that in this thread, so I simply returned the favor. Who gives you the right to decide what I can write and not?
    I respect your opinion, Michael, as I think you're a knowledgeable person with experience and a critical mind. But I think I was sharing important information, to someone that may not know, or wants to know, the minute differences between the developers or why they work the way they do. He just wanted to know what developer to use, and you know that he'll get as many replies here on APUG as there are individual posters. He was asking for advice. And I gave mine.


    Quote Originally Posted by Michael R 1974 View Post
    Give me a break. The original question was whether one was better than the other. Discussing how they are different (not better or worse) can help someone make a more informed decision regarding which one to pick first (depending on what format they shoot etc), and then they can focus on mastering it with consistency, control and creativity. I'm not talking about debating microsopic differences, but simply being aware of basic, visible properties.

    I'm just saying that "pick something and learn to use it" should not be the default answer to technical questions. Otherwise we might as well have only one forum with an automated "learn to use it" response.
    Last edited by Thomas Bertilsson; 08-02-2011 at 10:22 AM. Click to view previous post history.
    "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. #147

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    Point taken. No hard feelings I hope!

  8. #148
    Thomas Bertilsson's Avatar
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    Quote Originally Posted by Michael R 1974 View Post
    Point taken. No hard feelings I hope!
    None at all. It's all good.
    "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

  9. #149
    Bob Carnie's Avatar
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    Ok , I am going back quite a bit here so bear with me.

    I got turned on to Pyro by Gordon Hutchings early 90's, at that time I had a small shop in Toronto printing for commercial photographers , before photoshop so there was big budgets and lots of film, I was using a lot of graded paper at the time and experimenting with split printing.

    I do not believe everything I read or hear, so when people were boasting of the benifits of pyro I was curious.

    so I did a lot of testing, and I mean a lot, included were some pretty good fine art photographers who were working only in BW.
    We secured tons of films and did basically the one light source or high lighting range situation with different films and developers, we underexposed, normal exposed, overexposed with different times , under normal and push.
    Then we made prints to 20 x24 to look at the results.

    I followed Gordon Hutchings notes to a tee, and included this new to me developer into the mix.

    In every case where strong lighting conditions were the source, myself and each photographer picked the pyro negs.. that were overexposed and drop developed as per Hutchings notes.
    In every case the highlights were better defined and so too were the shadows.
    This was with graded paper and all efforts were made to match the overall print.

    Later came split printing which is not part of this thread, but it too opened more doors.

    I think that each and everyone watching this thread should do this test, and see what their eyes are telling them, Pyro or Pyrocat vs Xtol or D76- same scene and pump up the lighting contrast.
    Put the negatives and make prints, try to match and see which one works for you.

    Michael I only can say that in every situation where there is strong lighting I recommend a staining/tannin/hardening developer with overexposure and under dev.
    I am printing a show right now , 8x10 tri x in Pyro, indoor with window light only no flash and extreme long exposures to get the image.
    I am absolutely certain that if we used D76 , the prints would not have the range that I am pulling out of them.
    When you are at the extremes and trying to make a full tone print, there is a point of no return, blacks block up , highlights bloom and flare and go soft no matter how hard you try to burn in.

    Remember the days of 7 to 8 stop burn ins on graded paper to bring in detail?
    People resorting to hot water and finger development, muddy highlights.
    Highlights not coming in no matter wtf you did.

    When I brought Pyro into our workflow and split printing on VC paper those days are gone.
    Probably dosen't answer you well but I am believing my eyes , rather than scientific proof or what is written, remember I did not immediately believe what Hutchings had to say.
    Fred Picker wrote a lot about printing, I have all his notes, and books, his best advice was to test for yourself and see the results.





    Quote Originally Posted by Michael R 1974 View Post
    No no. I mean silver does not migrate. That's only one effect. There are still other things that enhance accutance and value discrimination in the tanned negative, like less halation and irradiation, and a lower probability of infectious development. I'm just suggesting people not go nuts thinking a stained negative will show massively different highlights than a well exposed/processed negative using a non-staining developer. I'd also add if exposure is heavy with Pyro/Cat, which several people on this thread have said they prefer, the enhancements pretty much go out the window. Sandy King has written alot about this stuff in other forums etc. For what it's worth I've done alot of my own experiments.

    I'm curious though about your flared-out D76 comment. Why does it have to be so? I agree there can be *slightly* more "bloom" around such objects with a sulfite developer than a staining developer, but the value differences and detail can be just as good, albeit harder to print in some cases. Can you explain?

  10. #150
    Ian Grant's Avatar
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    Quote Originally Posted by Bob Carnie View Post
    So you are saying the bare bulb in a room effect , one flared out* D76* , one crystal clear*Pyro* is a placebo effect and not real.

    I think I need an asprin, I have sold all this development based on this percieved effect.
    That effect is shown clearly in Hans Windisch's 1938 book
    "Die Neu Foto Schule" (also published in English as The New Photo School) where he recommends what is now known as the Windisch surface developer. In fact's an older formula which he doesn't claim as his own.

    The principle is that a tanning developer hardens the emulsion proportionately to development so in areas of extreme exposure there's more hardening and less penetration of the developer,. This was very important with older thicker emulsions prior to the 60's some of which had poor antihalation backing and that halation was worse in the emulsion closest to the support.

    Modern emulsions will exhibit a less marked effect and will vary depending on the emulsion & staining developer used.

    Ian



 

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