PMK Pyro, Alternative Dilutions?

chuckroast · Dec 18, 2023

So, my multiyear experiments in higher than normal dilutions for Pyrocat-HD, D-23, and even DK-50 have shown me that there is sometimes good advantage for doing this, particularly for increasing sharpness.

I'm wondering if anyone has tried more dilute forms of PMK Pyro to get this effect as well. That is, something more dilute than 1+2+100. I realise that I cannot do low agitation with PMK. It's high aerial oxidation rate will cause all manner of streaking if it is not frequently diluted. But I am curious if anyone has fiddled with the proportions of the developer and what they discovered.

MarkS · Dec 19, 2023

I believe that Gordon Hutchings' "The Book of Pyro" mentions other dilutions from standard, but I can't find my copy right now. Since he invented PMK, chose its dilution, and wrote the book, that may provide your best answer.
I used PMK and 4x5 TXP-320 for many years, and sharpness was never an issue. Are you dissatisfied with your PMK results, and if so, in what format?
It's probable that your PMK dilution experiments would follow along with results from the similar Pyrocat, but only testing will give you your answer.

chuckroast · Dec 19, 2023

No dissatisfaction, just curiosity.

john_s · Dec 19, 2023

PMK does oxidize fast. If you were to use it more dilute, I think you'd best use a large volume and minimize exposure to air. I once developed a roll in standard PMK and as an experiment tried to develop a bit of exposed test film in the same developer immediately and got absolutely nothing. I tried it after noticing that longer development time did not result in more contrast, because the developer was finito at around 13minutes. A larger quantity probably would have worked better.

MarkS · Dec 19, 2023

Sorry chuckroast, didn't mean to throw any shade. I spent many years on the job doing film testing, and although I know how, it seems that I've lost the desire to experiment.
I wish you the best of luck- we all have our favorite methods for film and developing, and how else will we find them without trying things? john_s makes some good points, too.

chuckroast · Dec 19, 2023

MarkS said:
Sorry chuckroast, didn't mean to throw any shade. I spent many years on the job doing film testing, and although I know how, it seems that I've lost the desire to experiment.
I wish you the best of luck- we all have our favorite methods for film and developing, and how else will we find them without trying things? john_s makes some good points, too.

No offense taken. I'm just a curious fellow.

Carnie Bob · Dec 20, 2023

I have used PMK since day one , I met Gordon Hutchings at an event here in Toronto where he had prints up, it was a very nice camera store and gallery . His prints were outstanding with real definite highlight detail values that one does not get with some of the other developers.

I have modified my workflow with PMK in a couple of ways..
1. only do three times, 12 min for lower ISO films, 14 min for normal IS0 films and 16 min with a lower dilution for situations where I think the film is exposed in low light and would need a boost.

2. I use the same rotation on the rotary and I give a manual twist inversion when adding developer to ensure even flow. I use distilled water for the developer.
The biggest difference is I split development in two rounds of 1000ml where half the dev is done in lets say 7 min, then I capture this round for stain. and then I do a second round of 7 min to finish off.

This modification was done due to testing I did and I found that the first round developed and hardened the highlights and the second round allowed the shadows to build up and harden.

This is a great developer and really economical .
And yes for every run I have done I have used the stain and Hutchings originally proposed.

chuckroast · Dec 20, 2023

Carnie Bob said:
I have used PMK since day one , I met Gordon Hutchings at an event here in Toronto where he had prints up, it was a very nice camera store and gallery . His prints were outstanding with real definite highlight detail values that one does not get with some of the other developers.

I have modified my workflow with PMK in a couple of ways..
1. only do three times, 12 min for lower ISO films, 14 min for normal IS0 films and 16 min with a lower dilution for situations where I think the film is exposed in low light and would need a boost.

2. I use the same rotation on the rotary and I give a manual twist inversion when adding developer to ensure even flow. I use distilled water for the developer.
The biggest difference is I split development in two rounds of 1000ml where half the dev is done in lets say 7 min, then I capture this round for stain. and then I do a second round of 7 min to finish off.

This modification was done due to testing I did and I found that the first round developed and hardened the highlights and the second round allowed the shadows to build up and harden.

This is a great developer and really economical .
And yes for every run I have done I have used the stain and Hutchings originally proposed.

Could you describe what "lower dilution" means in case 1. please?

Carnie Bob · Dec 20, 2023

35ml - A
60ml - B
2000ml distilled water

16min development split into two 8 min runs

chuckroast · Dec 20, 2023

Carnie Bob said:
35ml - A
60ml - B
2000ml distilled water

16min development split into two 8 min runs

I'll have to investigate this, thanks!

Carnie Bob · Dec 20, 2023

chuckroast said:
I'll have to investigate this, thanks!

Buyer beware I use this for HP5 which has been taken in extreme situations

Doremus Scudder · Dec 20, 2023

I have optimized edge effects with PMK by reducing agitation for the second half of the development time.

I tray develop and shuffle through the stack of 4x5 sheet film once every 30 seconds to begin with (that's one flip every five seconds for six sheets). For the second half of development time, I increase the interval to once through every 60 seconds. This allows the development to begin and proceed evenly during the first half, when most of the development happens, but then encourages Mackie lines to build during the second half.

I've also experimented with stronger dilutions for increasing contrast/reducing time (which didn't help much) and with adding ascorbic acid to the developer (à la Rollo Pyro), which does seem to help if extra contrast is needed, but needs more testing.

Best,

Doremus

DREW WILEY · Dec 20, 2023

I've used PMK for all kinds of films. The only exception to the standard 1:2:100 dilution is 1:1:100 in the case of PanF only.

chuckroast · Dec 20, 2023

Doremus Scudder said:
I have optimized edge effects with PMK by reducing agitation for the second half of the development time.

I tray develop and shuffle through the stack of 4x5 sheet film once every 30 seconds to begin with (that's one flip every five seconds for six sheets). For the second half of development time, I increase the interval to once through every 60 seconds. This allows the development to begin and proceed evenly during the first half, when most of the development happens, but then encourages Mackie lines to build during the second half.

I love the idea of reducing agitation during the 2nd half of the cycle. I've always tank processed sheet film with framed hangers, but I've agitated every 15sec to avoid the dreaded PMK streaking. Based on my findings doing semistand and EMA discovery, I've concluded that streaking - at least for high dilution/low agitation - is very much sensitive to how the film is supported. It may be that I can do just what you suggest but use my now favorite Kodak #6 hangers which have almost no contact with the film.

Doremus Scudder said:
I've also experimented with stronger dilutions for increasing contrast/reducing time (which didn't help much) and with adding ascorbic acid to the developer (à la Rollo Pyro), which does seem to help if extra contrast is needed, but needs more testing.

Best,

Doremus

I wonder if increasing the alkalinity of Part B or just adding more of it would effectively make the development more aggressive. Have you ever measured the default pH of "proper" PMK?

Andrew O'Neill · Dec 20, 2023

What about Rollo Pyro, PMK's continuous agitation for rotary? I used it years ago ago.

chuckroast · Dec 21, 2023

Andrew O'Neill said:
What about Rollo Pyro, PMK's continuous agitation for rotary? I used it years ago ago.

I have no access to a rotary processor. I only have open rubber tanks and daylight Nikkor tanks all of which require me to be the agitator ... something I've oft been called....

Andrew O'Neill · Dec 21, 2023

chuckroast said:
I have no access to a rotary processor. I only have open rubber tanks and daylight Nikkor tanks all of which require me to be the agitator ... something I've oft been called....

I use the poor man's rotary processor... BTZS tubes

chuckroast · Dec 21, 2023

Andrew O'Neill said:
I use the poor man's rotary processor... BTZS tubes

It seems those are rather scarce in the wild. I do know that Steve Sherman has tubes of his own making.

Andrew O'Neill · Dec 21, 2023

chuckroast said:
It seems those are rather scarce in the wild. I do know that Steve Sherman has tubes of his own making.

Sadly, they are no longer made. I did however, make one specifically for 8x10 and semi-stand, that works okay. I prefer the manufactured one, though

chuckroast · Dec 21, 2023

a

Andrew O'Neill said:
Sadly, they are no longer made. I did however, make one specifically for 8x10 and semi-stand, that works okay. I prefer the manufactured one, though

Do you silver print or scan? I'd love to see some scans of your prints from semistand negs. (Because I am nosy.)

Andrew O'Neill · Dec 21, 2023

chuckroast said:
a

Do you silver print or scan? I'd love to see some scans of your prints from semistand negs. (Because I am nosy.)

I haven't silver printed since I got into Alt. processes back in 2009 but.... Here is a kallitype print of an old barn from a semi-stand HP5 8x10 negative, and a negative scan of the town of Greenwood, which was on TMY 8x10, semi-stand. Both Pyrocat-HD 1+1+240

DREW WILEY · Dec 21, 2023

The timing seems off. Stand processing in freezing conditions might have made sense back in the ice age, but not under current global warming conditions. Maybe you should test boiling water next. I did recently see a documentary about a WWI combat photographer who developed his film in the cold trenches under the darkness of night, using helmets borrowed from soldiers as his chemical tanks. Better than using helmets with bullet holes through them.

chuckroast · Dec 21, 2023

DREW WILEY said:
The timing seems off. Stand processing in freezing conditions might have made sense back in the ice age, but not under current global warming conditions. Maybe you should test boiling water next. I did recently see a documentary about a WWI combat photographer who developed his film in the cold trenches under the darkness of night, using helmets borrowed from soldiers as his chemical tanks. Better than using helmets with bullet holes through them.

That's how you get bulletproof highlights.

DREW WILEY · Dec 21, 2023

I just wonder what their hair smelled like wearing the same helmets afterwards, or even if they still had hair? But they had worse things to worry about. Pyrogallol residue would have given the scalp a nice tan.

john_s · Dec 21, 2023

Wasn't pyrogallol used in hair dyes until fairly recently?

edit: see this toxicology report

https://ntp.niehs.nih.gov/sites/default/files/ntp/htdocs/chem_background/exsumpdf/pyrogallol_508.pdf

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