why Pyrocat?

Discussion in 'B&W: Film, Paper, Chemistry' started by bobwysiwyg, Apr 21, 2013.

  1. bobwysiwyg

    bobwysiwyg Subscriber

    Messages:
    1,623
    Joined:
    Mar 28, 2008
    Location:
    Ann Arbor, M
    Shooter:
    Multi Format
    I use both 35mm and 4x5. I shoot mostly B/W processing my own using D76. I've been interested in trying other developers and have seen frequent references to Pyrocat. Can anyone explain it's virtues or pros and cons for me. Oh, I've generally been using T-Max film if it matters. Any input would be appreciated.
     
  2. Rudeofus

    Rudeofus Subscriber

    Messages:
    2,396
    Joined:
    Aug 13, 2009
    Shooter:
    Medium Format
    Catechol (aka pyrocat) and Pyrogallol are developers which will not only form image silver, but also form a brown stain wherever silver was developed. This gives some degree of image amplification or less grain for same density. Historically Pyrogallol was prefered, but since it is very toxic people moved to Catechol.

    There are many resources dedicated to pyrocat developers which list mixing and developing instructions together with properties of their concoctions.
     
  3. Jim Noel

    Jim Noel Member

    Messages:
    2,057
    Joined:
    Mar 6, 2005
    Shooter:
    Large Format
    Pyrocat is preferred by many current workers over pyrogagallol (pyrogallic acid) for several reasons.
    1. somewhat less toxic although gloves should be worn with both.
    2. The stain is less intense, but a part of the spectrum which provides for more contrast in the print.
    3. The stain masks the grain of the film.
    4. the printing time is usually shorter than for pyrogallol negatives.
    5. Both forms of pyro tan the emulsion providing more protection from scratches.
    6. Separation in the highlights is superb when compared to MQ or PQ developers
    7. It is probably the cheapest developer around when diluted to working dilutions.
    8. if mixed in polyethylene glycol, which it should be, it lasts for an extreme length of time. I have never had any go bad.
    9. the scale of the negative is enhanced because the film curves don't have unusual fluctations.
    10. since the concentrates are liquids, it is quick to get ready for use.

    I can go on, but this should be enough. By the way,I have spent considerable time over the past 70 years working with various develoers and currently still maintain solutions of four different pyro develpers. Pyrocat HD+ is my absolute favorite.

    Jim
     
  4. pdeeh

    pdeeh Member

    Messages:
    2,991
    Joined:
    Jun 8, 2012
    Location:
    UK
    Shooter:
    Multi Format
    Do you mean Propylene glycol?
     
  5. Michael R 1974

    Michael R 1974 Subscriber

    Messages:
    6,200
    Joined:
    Feb 2, 2010
    Location:
    Montreal, Ca
    Shooter:
    Multi Format
    First ask yourself what sort of direction you want to move in vs stock D-76. Asked another way, what specifically don't you like about it, or what specifically you are looking for. That will help a lot, because much of what is written about staining developers is more myth than anything else. For example, "highlight separations" are frequently talked about. I found no advantage over a moderately diluted solvent developer like D-76, nor does rational sensitometry support this notion. Another strange argument concerns "grain masking". For one thing the formulators are careful to point out this effect (combined with lower silver densities) can lead to finer grain in comparison to non-staining high definition developers, not in comparison to solvent developers. The other interesting thing about grain masking is it requires the spreading of dye. This would appear to contradict the purported effects of tanning and reduced "migration" (questionable) on acutance.

    Much of my photography is dones under extreme subject contrast conditions. I worked a lot with PMK and WD2D+ Pyro formulas. They are fine developers, but not magical. The Pyrocat formulas developed by Sandy King use Catechol. The most common version is the Phenidone-Catechol Pyrocat HD. I have never used it but it has a fine reputation. It also appears to be more flexible than the above mentioned Pyro formulas in that people use it with rotary processing, reduced agitation techniques and some even use it as a two bath.

    Just remember, you don't get something for nothing. You can't have both high acutance and fine grain, and you can't have both highlight compensation and enhanced highlight separation. There is no "free lunch".
     
  6. bobwysiwyg

    bobwysiwyg Subscriber

    Messages:
    1,623
    Joined:
    Mar 28, 2008
    Location:
    Ann Arbor, M
    Shooter:
    Multi Format
    Michael, excellent question. I can't say I dislike anything about D76. Probably more curiosity. Good food for thought. Thank you for your candor.
     
  7. Michael R 1974

    Michael R 1974 Subscriber

    Messages:
    6,200
    Joined:
    Feb 2, 2010
    Location:
    Montreal, Ca
    Shooter:
    Multi Format
    I don't want to discourage you from trying these things, of course. Just have a healthy skepticism. In the end, trying for yourself is often the best way to figure things out when it comes to this stuff, because there is very little in the way of objective data out there. Just work with it yourself and decide if you like it. Pyrocat is probably a good one to try because it seems it is more forgiving and flexible than some other staining developers. Something to keep in mind: Don't try to evaluate stained negatives by eye, because you're really only seeing the silver density, not the additional stain density the paper will "see". Even densitometry is less than straight forward. So make prints. A stained negative that looks too thin and low in contrast might print just right.
     
  8. Ian Grant

    Ian Grant Subscriber

    Messages:
    17,521
    Joined:
    Aug 2, 2004
    Location:
    West Midland
    Shooter:
    Multi Format
    Agree 100% with what Jim says, I've tried a lot of developers over the last 50 years and it's the best alround developer I've found, consistenly excellent results and negatives that are remarkably easy to print.

    Ian
     
  9. Ed Bray

    Ed Bray Member

    Messages:
    348
    Joined:
    Nov 23, 2011
    Location:
    Plymouth, UK
    Shooter:
    Multi Format
    This is the first of my images from negatives that I processed using Divided Pyrocat HD which is supposed to give a compensating effect to high contrast situations, although I normally use Pyrocat HD in its mixed form I thought I would try the divided Pyrocat HD as I wanted to get some detail from the semi-circle window. I am very pleased with the compensating effect, I could not believe the amount of detail from the semi-circular windows bearing in mind how high the contrast between the light outside and the very dark conditions inside.
    The measured exposure was 30 secs @ f45 at ISO25, although the exposure I actually gave was 4 minutes at f45 on Adox CHS25 which will give an idea of how dark it was although I did allow 1 stop for reciprocity and I also had the Centre Filter on the 72mm Super Angulon XL which ate up another 2 stops.
    [​IMG]
    Redundant Pressure Filters (Tottiford Water Treatment Works) by Ed Bray, on Flickr
     
  10. HTF III

    HTF III Restricted Access

    Messages:
    133
    Joined:
    Apr 18, 2013
    Shooter:
    Multi Format
    You see all these claims as to how poisonous it is, but at one time it was used as a hair dye (pyrogallol). The same article I read also says metol and hydroquinone are poisonous. I wonder if pyro is really all that dangerous, or is it dangerous by today's standards, where EVERYTHING is poisonous. I'm thinking of switching to it after everything I've read on this site.
     
    Last edited by a moderator: Apr 21, 2013
  11. markbarendt

    markbarendt Subscriber

    Messages:
    6,671
    Joined:
    May 18, 2008
    Location:
    Beaverton, OR
    Shooter:
    Multi Format
    This is so true.
     
  12. bobwysiwyg

    bobwysiwyg Subscriber

    Messages:
    1,623
    Joined:
    Mar 28, 2008
    Location:
    Ann Arbor, M
    Shooter:
    Multi Format
    Thanks all for your input. I've decided to give it a try. Just ordered some (SandyK's formula) from Photographer's Formulary.
     
  13. Klainmeister

    Klainmeister Member

    Messages:
    1,493
    Joined:
    Jun 2, 2010
    Location:
    Santa Fe, NM
    Shooter:
    4x5 Format
    If you're anything like me, you'll find advantages and disadvantages to any developer. I have been using Pyrocat for about 5 years now, mainly because I can actually see an increased acutance in my images vs D76. That being said, I also use Xtol to accomplish a different look. Ultimately, it's best to do some side by side comparisons and see the strengths/weaknesses of each. For how much the chemistry costs, it's a no brainer when it comes to overall expense vs what can gained.
     
  14. john_s

    john_s Member

    Messages:
    1,094
    Joined:
    Nov 19, 2002
    Location:
    Melbourne, A
    Shooter:
    Medium Format
    If you eat smoked meats you are ingesting little doses of pyrogallol. Not good if that's all you eat.
     
  15. Michael R 1974

    Michael R 1974 Subscriber

    Messages:
    6,200
    Joined:
    Feb 2, 2010
    Location:
    Montreal, Ca
    Shooter:
    Multi Format
    Uh oh. I practically live on smoked meat...
     
  16. MattKing

    MattKing Subscriber

    Messages:
    15,211
    Joined:
    Apr 24, 2005
    Location:
    BC, Canada
    Shooter:
    Multi Format
    Ah, Montreal ......
     
  17. HTF III

    HTF III Restricted Access

    Messages:
    133
    Joined:
    Apr 18, 2013
    Shooter:
    Multi Format
    Just what I thought. Pyro is no more dangerous than anything else I get all over my hands every day. Thanks. I'm going to get some.
     
  18. markbarendt

    markbarendt Subscriber

    Messages:
    6,671
    Joined:
    May 18, 2008
    Location:
    Beaverton, OR
    Shooter:
    Multi Format
  19. Michael R 1974

    Michael R 1974 Subscriber

    Messages:
    6,200
    Joined:
    Feb 2, 2010
    Location:
    Montreal, Ca
    Shooter:
    Multi Format
    You're concluding things about the toxicity of these compounds based on smoked meat??? PLEASE read some proper documentation regarding the safe handling of Pyrogallol and Catechol (not to mention other compounds used in darkroom chemistry).
     
  20. PhotoJim

    PhotoJim Member

    Messages:
    2,223
    Joined:
    Oct 9, 2005
    Location:
    Regina, SK,
    Shooter:
    Multi Format
    A lot of these are not advantages over pyrogallol in some formulations:

    5. Tie.
    6. Similar. Virtually a tie; it just depends on your preferences.
    7. I'd have to crunch the numbers, but most pyrogallol developers like PMK are very inexpensive to use.
    8. PMK lasts for years mixed in distilled water. It does not require propylene glycol when mixed.
    9. Tie.
    10. Tie.

    I don't mean to badmouth pyrocatechin developers, merely to point out that PMK has few disadvantages compared to them.

    Incidentally, and not related to the original poster, "pyrocat" is the name of a series of formulations using pyrocatechin aka catechol aka catechin (which are all the same developer). I'm not sure, OP, if you were talking about one of these formulas or if you were talking about pyrocatechin.
     
  21. HTF III

    HTF III Restricted Access

    Messages:
    133
    Joined:
    Apr 18, 2013
    Shooter:
    Multi Format
    Far be it for me to call the following source a hallmark of credibility, but I found this to be interesting. If I'm concluding right (which is a stretch), maybe using pyro would actuall be good for me as someone who smokes. Seems the parent acid from which pyrogallol is extracted is a chemical unfriendly to cancer cells. DON'T TAKE MY WORD FOR ANY CLAIMS.
    But then when we develop in a developing tank, pouring our chemistry from a beaker, there isn't a whole lot of hand contact any way.
    http://en.wikipedia.org/wiki/Gallic_acid
     
  22. bobwysiwyg

    bobwysiwyg Subscriber

    Messages:
    1,623
    Joined:
    Mar 28, 2008
    Location:
    Ann Arbor, M
    Shooter:
    Multi Format
    Sorry but I know enough to answer this.:smile:
     
  23. Tony-S

    Tony-S Member

    Messages:
    764
    Joined:
    Aug 16, 2009
    Location:
    Fort Collins
    Shooter:
    Multi Format
    In all likelihood, it is a clinically irrelevant compound for cancers.
     
  24. Jim Noel

    Jim Noel Member

    Messages:
    2,057
    Joined:
    Mar 6, 2005
    Shooter:
    Large Format
    OOPS - YES PROPYLENE OR POLYPROPYLENE not ehthylene.
    Thanks for the heads up.
     
  25. Andrew O'Neill

    Andrew O'Neill Subscriber

    Messages:
    1,005
    Joined:
    Jan 16, 2004
    Location:
    Coquitlam, B
    Shooter:
    8x10 Format
    Hi Jim, why should it be mixed in polyethylene glycol? If the only reason is indefinite shelf life, that's great for the casual user, but I go through pyrocat stock rather quickly, so for me, there is no point to mixing in polyethylene glycol... unless I'm missing something. Up here in Canada, polyethylene is pretty expensive.