PMK verses Pyrocat-HD

Isn't it true that when one substitutes various chemicals in a formula, you are really formulating another developer? Is the pyrocat hd still pyrocat hd if you substitute ANY of the chems for another? Isn't that what happened when Sandy King introduced the various changes in the original Pyrocat HD?

lee\c

dslater said:

Yes - but I was talking about the general stain - not the image stain. My observations on general stain were based on the appearance of deep shadows and the unexposed edges of the film.

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IMHO,transmission densitometry is the best way to evaluate stain - both image stain and general stain.

And, if you bleach the developed film the stain (if it exists) will remain.

Preservation of both Deep shadow detail and Highlight detail is a particular attribute of the Pyrocat family of developers.

Let's try and correct the record.

Staining developers are an asset for both VC and graded papers. The yellow-yellow green - orange brown stain with PMK retards blue and green light. The stain with PMK is proportional to the silver density. VC papers are sensitive to both blue and green light and graded papers are sensitive to blue light. The color of the stain retards the transmission of blue and green light and thus is effective for both types of papers.

Shadows with PMK are not muddy if the proper exposure is given to the negative. You should always test for your personal EI - however you do the testing you should aim for a zone 1 density of .1 above fb+f.

I did a test a few years ago with PMK and Pyrocat. I tested for EI and dev time for a vc paper with no filter - approx the same as a #2 filter. I then shot side by side comparisons, processed the film and made direct scans of the negatives. The PMK negative had much better high value separation. I would have been happy to change developers if the Pyrocat gave me better tonal separation up and down the scale. I did not feel it did.

If you have not read The Book of Pyro by Gordon Hutchings I would strongly recommend doing so. It is the most definitive and comprehensive work on staining develpers and how they work. You can get a copy form Bostick and Sullivan or the Photographer's Formulary. Gordon will also be doing a workshop and a presentation on staining developers at foto3.


steve simmons
www.viewcamera.com

palewin said:

I was hoping Sandy King would reply to this thread, as he is the developer of the Pyrocat family of developers.

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Given that the thread title was "PMK versus Pyrocat-HD" I decided it best to not make any substantive comment comparing the two formulas. To the extent possible I would like to avoid entanglement in any more pyro wars, which I put more or less in the category of bad wine That is, if I never have any more of it in this lifetime I have already had enough for this life, and for all eternity.

Sandy King

well thats a pity. I'm not asking which is best because there is no such thing. I am asking what is the difference on only graded papers between the two developers. I would be more than happy to know one is better for highlight separation and one is better for shadow separation because that would give me two different tools for two different requirements. But if they are both very similar then I will only test one (for now).
So far I've a couple people say there's no real difference in the print and one person say there is a major difference. That leaves me having to test both developers.

steve simmons said:

Let's try and correct the record.

Staining developers are an asset for both VC and graded papers. The yellow-yellow green - orange brown stain with PMK retards blue and green light. The stain with PMK is proportional to the silver density. VC papers are sensitive to both blue and green light and graded papers are sensitive to blue light. The color of the stain retards the transmission of blue and green light and thus is effective for both types of papers.

Shadows with PMK are not muddy if the proper exposure is given to the negative. You should always test for your personal EI - however you do the testing you should aim for a zone 1 density of .1 above fb+f.

I did a test a few years ago with PMK and Pyrocat. I tested for EI and dev time for a vc paper with no filter - approx the same as a #2 filter. I then shot side by side comparisons, processed the film and made direct scans of the negatives. The PMK negative had much better high value separation. I would have been happy to change developers if the Pyrocat gave me better tonal separation up and down the scale. I did not feel it did.

If you have not read The Book of Pyro by Gordon Hutchings I would strongly recommend doing so. It is the most definitive and comprehensive work on staining develpers and how they work. You can get a copy form Bostick and Sullivan or the Photographer's Formulary. Gordon will also be doing a workshop and a presentation on staining developers at foto3.


steve simmons
www.viewcamera.com

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Steve, Just wanting to make sure I understand your statements.

Did you base your opinion of high value separation on digital scans of your PMK and Pyrocat developed negatives?

If so, what were the separation measurand(s) you used? What did you use as an experimental control?

Steve, Just wanting to make sure I understand your statements.

Did you base your opinion of high value separation on digital scans of your PMK and Pyrocat developed negatives?

Yes.

If so, what were the separation measurand(s) you used? What did you use as an experimental control?


measurand(s)

??????????????????


I compared the Pyrocat and PMK negs against each other.

It is not really important, IMHO, which formula you use. The point of my post was to state that there are advanatges for both VC and graded papers when using a staining developer where the stain is proportional to the silver density as it is with both PMK and Pyrocat.

steve

lee said:

Isn't it true that when one substitutes various chemicals in a formula, you are really formulating another developer? Is the pyrocat hd still pyrocat hd if you substitute ANY of the chems for another? Isn't that what happened when Sandy King introduced the various changes in the original Pyrocat HD?

lee\c

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I will comment on this since it involves only Pyrocat.

Yes, I agree with Lee. Any change one makes to a formula may have intended and unintended consequences. There is a family similarity between the various developers in the Pyrocat family, which include Pyrocat-HD, Pyrocat-MC (which are offered in commercial kits) and also Pyrocat-PC, which must be mixed from scratch at this time. However, objective testing would show some differences in characteristics between these formulas which might favor one or the other with a given set of conditions.

To consider how significant the changes might be, just realize that merely increasing the amount of sodium sulfite in the Pryrocat-HD formula from 10 grams to 40 grams per liter of Stock A would make the formula non-staining.


Sandy King

leicam5 said:

So, 133 gr. of Pyrocat instead of 100 gr. of pyrogallol will do well too?

Philippe

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What would you dissolve it in? I have a hard enough time dissolving 100 g pyrocatechin in a liter of propylene glycol. The ratios are about equal in activity given all else the same. We're already only using 20 ml of stock to make a liter of ordinary working solution, and 10 or less for stand development. BTW, the abbreviation "gr" means grains, of which there are about 15.3 to the gram.

MY only purpose in exchanging the two agents was to change the color of the stain, and to show that it can be done using the developing strategy, so to speak, of Sandy King with pyrogallol as the agent. If you want to try catechol in place of pyrogallol using the strategy of Gordon Hutchings, I can't tell you if it will work because I haven't tried it. I don't have catechol on hand, so you will have to try it yourself. I could try it with hydroquinone, which we know can make a good developer with Metol, sulfite and a little borax, and also with Metol, ascorbic acid and borax, but whether or not either it or catechol will stain at the pH of PMK, I do not know. Hydroquinone stain is different from either catechol or pyrogallol.

I think you could get the same effect from Pyrocat MC by using more of the A solution and TEA or the PMK Kodalk solution as B. That I can try because I have some Pyrocat MC on hand,

steve simmons said:

Let's try and correct the record.

Staining developers are an asset for both VC and graded papers. The yellow-yellow green - orange brown stain with PMK retards blue and green light. The stain with PMK is proportional to the silver density. VC papers are sensitive to both blue and green light and graded papers are sensitive to blue light. The color of the stain retards the transmission of blue and green light and thus is effective for both types of papers.

Shadows with PMK are not muddy if the proper exposure is given to the negative. You should always test for your personal EI - however you do the testing you should aim for a zone 1 density of .1 above fb+f.

I did a test a few years ago with PMK and Pyrocat. I tested for EI and dev time for a vc paper with no filter - approx the same as a #2 filter. I then shot side by side comparisons, processed the film and made direct scans of the negatives. The PMK negative had much better high value separation. I would have been happy to change developers if the Pyrocat gave me better tonal separation up and down the scale. I did not feel it did.

If you have not read The Book of Pyro by Gordon Hutchings I would strongly recommend doing so. It is the most definitive and comprehensive work on staining develpers and how they work. You can get a copy form Bostick and Sullivan or the Photographer's Formulary. Gordon will also be doing a workshop and a presentation on staining developers at foto3.


steve simmons
www.viewcamera.com

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Can you please confirm that your comparisons were done using scans of negatives and NOT prints to paper direct from the negatives.

sanking said:

Given that the thread title was "PMK versus Pyrocat-HD" I decided it best to not make any substantive comment comparing the two formulas. To the extent possible I would like to avoid entanglement in any more pyro wars, which I put more or less in the category of bad wine That is, if I never have any more of it in this lifetime I have already had enough for this life, and for all eternity.

Sandy King

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Hi Sandy,
I have witnessed a number of these pyro wars and I can hardly blame you for staying away. It's unfortunate and is a loss for the rest of us.

Measurand

steve simmons said:

Steve, Just wanting to make sure I understand your statements.

Did you base your opinion of high value separation on digital scans of your PMK and Pyrocat developed negatives?

Yes.

If so, what were the separation measurand(s) you used? What did you use as an experimental control?


measurand(s)

??????????????????


I compared the Pyrocat and PMK negs against each other.

It is not really important, IMHO, which formula you use. The point of my post was to state that there are advanatges for both VC and graded papers when using a staining developer where the stain is proportional to the silver density as it is with both PMK and Pyrocat.

steve

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Thanks, Steve.

Measurand: A measurand is a physical parameter being quantified by measurement.

One can visually (and via reflection densitometry) compare prints made with PMK, Pyrocat and D-76 developed negatives contact printed on Silver Chloride paper, Pt paper, and/or PtPd paper.

We have in general been discussing here two different strategies of staining film development and at least two different spectra of stains. Anyone who thinks we are going to find one best strategy and/or one best color is mistaken. My hope was to show that either strategy or either stain color can be combined to make at least 4 different developers which can serve at least 4 different purposes.

We know that the strategy involving high dilution with relatively high pH but low buffering capacity can be used to stain with either pyrogallol or catechol. Development by such solutions is noted for high resolution and sharpness by use of standing development.

Reasonably high dilution with lower pH but greater buffering has somewhat different aims which have been successfully achieved by PMK using pyrogallol with sodium metaborate as alkali.

I see no need for any kind of war. It's like deciding whether a cook must use only salt or pepper. Once the choice to use salt is made, pepper must never again be used.

If I can keep a bottle of a mixture of catechol, p-aminophenol and ascorbic acid in propylene glycol and another of a mixture of pyrogallol, metol and ascorbic acid, and a bottle of triethanolamine or Kodalk solution and a bottle of 75% K2CO3 and have my choice of stain color and other image qualities, why should I not? And if I don't want stain, I can add some sulfite. I could clear out all but 4 or 5 of the myriad of bottles I have with different developers that must be periodically pitched anyway and still have everything I have now.

I should have pointed out that the most probable cause of a general stain in any staining developer is base fog. The developer is not smart enough to know which is image silver and which is base fog. To prove me wrong, fix a piece of unexposed film, wash it, and try to develop a stain on it with any staining developer. Now develop a piece of unexposed film in a non-staining developer, fix it, wash it and try to develop a stain in its fog silver with a staining developer. Now develop a piece of unexposed film in a staining developer and see if you get a base stain. These test strips should give you a clue as to how to prevent the overall stain.

gainer said:

What would you dissolve it in? I have a hard enough time dissolving 100 g pyrocatechin in a liter of propylene glycol. The ratios are about equal in activity given all else the same. We're already only using 20 ml of stock to make a liter of ordinary working solution, and 10 or less for stand development. BTW, the abbreviation "gr" means grains, of which there are about 15.3 to the gram.

MY only purpose in exchanging the two agents was to change the color of the stain, and to show that it can be done using the developing strategy, so to speak, of Sandy King with pyrogallol as the agent. If you want to try catechol in place of pyrogallol using the strategy of Gordon Hutchings, I can't tell you if it will work because I haven't tried it. I don't have catechol on hand, so you will have to try it yourself. I could try it with hydroquinone, which we know can make a good developer with Metol, sulfite and a little borax, and also with Metol, ascorbic acid and borax, but whether or not either it or catechol will stain at the pH of PMK, I do not know. Hydroquinone stain is different from either catechol or pyrogallol.

I think you could get the same effect from Pyrocat MC by using more of the A solution and TEA or the PMK Kodalk solution as B. That I can try because I have some Pyrocat MC on hand,

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Dear Mr Gainer,

Forgive me my ignorance as well as the 'metric confusion' I might have provoked.

I was just considering the fact that Pyrogallol is, at my supplier, about 3x more expensive than Pyrocatechol.
And, I am still looking for a good and workable paper developer based on Pyrocatechol (+ Phenidone and Vit-C) and no Metol nor Hydrochinon to which I seem to be allergic. In my rather idle search, all the formula's I found, till now, were based on Pyrogallol, and the one, with Pyrocat, hardly lasted for a few hours in the open dish, but the image colour was precisely what I was looking for, a pity.

But, for film, Sandy King's Pyrocat HD (mixed in de-mineralised water) is my number one, for 3/4 of the job's, the rest I reserve for Rodinal ( + borax, as you very well suggested).

And Yes, grams, annotated in short, is g (All tough 'Imperial measure users' tend to write gm). But, apparently, we are not the only ones struggling with this ( see : CNN - NASA's metric confusion caused Mars orbiter loss - September 30, 1999 ).

Philippe

Philippe,

here is a good pyro developer that you can leave out the Pyrogallol and add 5 g of citric acid that will last all day in an open tray. Use de-mineralized water. Don't freak out that the developer is orange. Gives strong blacks nice highlites and good mid tone graduation. If it is not clear this is a paper developer.

http://unblinkingeye.com/Articles/PyroPlus/pyroplus.html

lee\c

"BTW, I am a Pyrocat-MC user. Most of my development is with minimal or semi-stand agitation. BTW, I get excellent results with Sheet film. 35mm and 120 roll film as well.
__________________
Tom Hoskinson"

I agree with Tom about the MC. I develop Tmax 400 in MC in a Jobo and the results are excellent. My neighbor and I both do LF and have darkrooms so we spend much time comparing notes. My first negs with this combination took our breath away....EC

dslater said:

Hi Sandy,
I have witnessed a number of these pyro wars and I can hardly blame you for staying away. It's unfortunate and is a loss for the rest of us.

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Just to clarify, I have no intention to avoid all discussions of pyro developers. To the contrary, as the creator of the Pyrocat family I am happy to provide information about the qualities and recommendations for development of these developers whenever I can.

However, I don't promote the Pyrocats by criticizing other developers, and certainly not PMK, which was my primary developer for over ten years. In fact, part of the genesis of Pyrocat-HD is directly related to my use of and knowledge of how PMK works. My main goal was to produce a formula that would work well in BTZS tubes and with stand development and I felt that the use of pyrocatechin, which oxidizes more slowly than pyrogallol, might work better in these two specific applications.

In answer to Rob's original question, I think he would be very happy with either PMK or Pyrocat-HD. They are much more like each other than either is to a traditional developer like D76. Just pick one and learn to use it would be my advice.

Sandy King

I am very happy with the Pyrocat-HD (glycol) / T-Max 100 combination as a nimble solution to do just about anything. I print these negs with a V-54 cold light lamp and the results are quite nice. Over time I think I have cut down on the amount of paper I use due to the relative ease of printing these negs. My previous combination was Bergger / PMK which was wonderful but more difficult to pin down precisely.

lee said:

Philippe,

here is a good pyro developer that you can leave out the Pyrogallol and add 5 g of citric acid that will last all day in an open tray. Use de-mineralized water. Don't freak out that the developer is orange. Gives strong blacks nice highlites and good mid tone graduation. If it is not clear this is a paper developer.

http://unblinkingeye.com/Articles/PyroPlus/pyroplus.html

lee\c

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Thank you Lee, I will certainly try this one!

Philippe

So far I have found that I can use pyrogallol or catechol in the part A of Pyroxxx MC. Different colored stains result, as one would expect. The amount of pyrogallol needs be only 2/3 the amunt of catechol for similar activity. I have also learned that Pyrocat MC A used with PMK B in the proportions 1:1:25 makes very good FP4+ negatives by stand development for 24 minutes. I am about to test PMK A with the carbonate B of the Pyrocat series. I suspect the higher pH will require more dilute solution or shorter development times. If it seems to be something an old man would do to keep from being bored, you are right.

What I am trying to learn is how few stock solutions must be kept in order to have at hand the choice of the two different colored stains as well as the choice of the other characteristic differences between Pyrocat XX and PMK developers.

FP4 with PyrocatMC is the best combinations for me, use dilutions 1:4:100 semistand 24 minutes

gainer said:

So far I have found that I can use pyrogallol or catechol in the part A of Pyroxxx MC. Different colored stains result, as one would expect. The amount of pyrogallol needs be only 2/3 the amunt of catechol for similar activity. I have also learned that Pyrocat MC A used with PMK B in the proportions 1:1:25 makes very good FP4+ negatives by stand development for 24 minutes. I am about to test PMK A with the carbonate B of the Pyrocat series. I suspect the higher pH will require more dilute solution or shorter development times. If it seems to be something an old man would do to keep from being bored, you are right.

What I am trying to learn is how few stock solutions must be kept in order to have at hand the choice of the two different colored stains as well as the choice of the other characteristic differences between Pyrocat XX and PMK developers.

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Very interesting. Thanks for posting these results. I am surprised that you got that much developer activity from the Pyrocat MC A with the PMK B solution. I tried it a couple of times and never saw much activity, but I did not use nearly as much of B solution as you have used. As for PMK A with Pyrocat B I am certain that you will have to shorten development time a lot, or use a weaker dilution as the different in working pH will be very great, about 9.6 for metaborate compared to about 10.9 with carbonate.

Sandy

A snip test showed I needed 1 part of PMK A, 1 part of Pyrocat B and 100 parts of water to get the developing time down to about 8 minutes. It works, but I don't care much for the gradations. I have to start a new test roll to be sure, as I only had one complete frame left of the bracketted exposures, but even though all the detail was visible in the negative, it seemed to be too much soot and charcoal, and MG filtering didn't seem to be the cure. These are times when I wish for a 3-color densitometer.

The Pyrocat A + metaborate seemed to be something like 1/4 the activity of the usual Pyrocat working solution. I didn't feel like attending to a long period of agitation, so took a chance on the 24 minutes of standing. I didn't even do the semi- part, just went off and watched the tube. There was no visible base fog on the FP4+ and the prints were easy to do from all three of the bracketted exposures. If anyone wants to try it, I diluted 2:2:50 and stood it for 24 minutes.

lee said:

Philippe,

here is a good pyro developer that you can leave out the Pyrogallol and add 5 g of citric acid that will last all day in an open tray. Use de-mineralized water. Don't freak out that the developer is orange. Gives strong blacks nice highlites and good mid tone graduation. If it is not clear this is a paper developer.

http://unblinkingeye.com/Articles/PyroPlus/pyroplus.html

lee\c

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Although this is a bit off-topic, it is very interesting. The article says that leaving out the pyrogallol gives low contrast results. Is that your experience, Lee? As was pointed out by a previous poster, pyrogallol is a lot more expensive than pyrocatechol. Is the citric acid only a preservative, or does it somehow make up for the lack of pyrogallol?