Processing 510 Pyro & 100TMX with Jobo CPP-2

[John Layton]

Truly sorry if this might sound pompous to some...but if realizing my vision requires chemistry which might be deleterious to my health (understanding that I do what I can to mitigate these effects)...so be it!

[Michael Kadillak]

Truly sorry if this might sound pompous to some...but if realizing my vision requires chemistry which might be deleterious to my health (understanding that I do what I can to mitigate these effects)...so be it!

Absolutely agree John. After one gets past the chat phase and truly commits oneself to the darkroom and objectively assesses their results ie. what "moves them" visually in mounting and framing a print that they will sign as their "best work", that is where the rubber meets the road. This entails that they have mastered the art of producing a quality negative from which they can work with. Like you I would put on a full body protective lab suit if need be for my chosen soup simply because the resultant print is directly proportional to the negative it is produced from. This is precisely why B&W photography is such an art form in that the vast array of chemical developers we can deploy have an equally enormous effect on the developer/negative interaction. Look at enough prints from the early days of photography to current in concert with what you are producing and the question of your personal choice in developer virtually resolves itself. Then you just need to figure out the safety issues if they exist.

[interneg]

In fact, I seem to recall that Kodak's own HC-110 does/did have a pyro component but that's from memory, I have no first source for this.

Catechol at various points - and in small quantities. It seems safe enough once in solution - and like HQ, I wouldn't bathe in the stuff in very high concentrations (far higher than film developers). All three of the Dihydroxybenzenes seem to have been very well researched by Kodak across a wide variety of uses (including as couplers etc) and further derivatives too - if catechol genuinely had advantages as a developing agent rather than as a scavenger or something like that (I recall) in HC-110, there's no question Kodak would have made use of it (for example, there are components in some emulsions that are used in the order of 7g/ 500kg of emulsion - because they have useful effects - even if they have to be expensively synthesised, so it's not a question of price or some sort of conspiracist nonsense - it's just that it probably offered no advantages over HQ under rigorous testing). From what I also recall, the only reason catechol is used in Pyrocat is because it produces a better stain (a dye coupler really) colour than HQ.

[Michael Kadillak]

Catechol at various points - and in small quantities. It seems safe enough once in solution - and like HQ, I wouldn't bathe in the stuff in very high concentrations (far higher than film developers). All three of the Dihydroxybenzenes seem to have been very well researched by Kodak across a wide variety of uses (including as couplers etc) and further derivatives too - if catechol genuinely had advantages as a developing agent rather than as a scavenger or something like that (I recall) in HC-110, there's no question Kodak would have made use of it (for example, there are components in some emulsions that are used in the order of 7g/ 500kg of emulsion - because they have useful effects - even if they have to be expensively synthesised, so it's not a question of price or some sort of conspiracist nonsense - it's just that it probably offered no advantages over HQ under rigorous testing). From what I also recall, the only reason catechol is used in Pyrocat is because it produces a better stain (a dye coupler really) colour than HQ.

Photography is not a theoretical art form that can effectively be extrapolated from manufacturers literature and wide eyed conjecture. Adjectives like "I also recall" and "seem to have been well researched by Kodak across a wide variety of uses" are completely meaningless in the broader context of meaningful results at the personal level relative to the topic in play. If you feel compelled to support a result that is in line with your "pyro is not what it is cracked up to be" conclusion they do us a favor and show us why you feel this way in the form of some example prints.

[tundra]

Truly sorry if this might sound pompous to some...but if realizing my vision requires chemistry which might be deleterious to my health (understanding that I do what I can to mitigate these effects)...so be it!

In 50 years of doing this, I've had a number of inflection points in which some technical "epiphany" or another opened up my work that translated directly into better aesthetic results:

- Finding out about and learning the baseline of Zone system
- Learning VC split printing
- Discovering how PMK (as an example of Pyro staining developers) could help me master very big SBRs without crushing mid-tone contrast
- Combining Pyro staining (via Pyrocat-HD) and semistand/high dilution development to create astonishingly better negatives and prints

Note that I do not claim that this is the ONLY way to achieve good results, but it was my way. Notice also that these discoveries built upon each other. Notice, most importantly, that the measure of any of these was- and is improving aesthetic output not improving measured data.

The only way the chemistry we're talking about here should remotely put your health at risk is if we're not practicing good, standard, lab precautions. I mean, we're not working with methyl mercury or cyanide gas for heaven's sake. I stipulate that if we are sloppy we can do some medical harm, but even the modicum of care taught in High School Chemistry likely would suffice ... (they DO still teach Chemistry right, or is it all social justice and emotional wellbeing these days???)

[sanking]

From what I also recall, the only reason catechol is used in Pyrocat is because it produces a better stain (a dye coupler really) colour than HQ.

Sorry, that is just not true, and if anyone should know it is me.

In a larger sense, the unique characteristic of tanning and hardening developers is not the stain, but hardening. Staining does have some incidental advantages for printing with VC silver papers, and in crafting negatives that print with different contrast with silver papers and some alternative processes, including pt/pd.

That said, it is hardening that results in more precise reduction, which gives Pyro gives more pronounced edge effects than other developers. This is due to the fact that there is much less migration of silver halide during development as hardening prevents the scattering of light which gives infectious development (spreading of silver development beyond the exact image boundaries. As a result of these effects Pyro is capable of more pronounced edge effects than other developers.

Of course, reduced agitation along with dilution are the keys to masterful use of Pyro staining and hardening negatives, and to that end I suggest farther reading of Steve Sherman's article on the subject, "Altering a Negative's Personality: Reduced Agitation Film Processing, at https://unblinkingeye.com/Articles/RASS/rass.html.

Sandy

[Michael Kadillak]

Sorry, that is just not true, and if anyone should know it is me.

In a larger sense, the unique characteristic of tanning and hardening developers is not the stain, but hardening. Staining does have some incidental advantages for printing with VC silver papers, and in crafting negatives that print with different contrast with silver papers and some alternative processes, including pt/pd.

That said, it is hardening that results in more precise reduction, which gives Pyro gives more pronounced edge effects than other developers. This is due to the fact that there is much less migration of silver halide during development as hardening prevents the scattering of light which gives infectious development (spreading of silver development beyond the exact image boundaries. As a result of these effects Pyro is capable of more pronounced edge effects than other developers.

Of course, reduced agitation along with dilution are the keys to masterful use of Pyro staining and hardening negatives, and to that end I suggest farther reading of Steve Sherman's article on the subject, "Altering a Negative's Personality: Reduced Agitation Film Processing, at https://unblinkingeye.com/Articles/RASS/rass.html.

Sandy

Thanks for the clarification Sandy. I was hoping this reached your radar screen.

[tundra]

Sorry, that is just not true, and if anyone should know it is me.

In a larger sense, the unique characteristic of tanning and hardening developers is not the stain, but hardening. Staining does have some incidental advantages for printing with VC silver papers, and in crafting negatives that print with different contrast with silver papers and some alternative processes, including pt/pd.

That said, it is hardening that results in more precise reduction, which gives Pyro gives more pronounced edge effects than other developers. This is due to the fact that there is much less migration of silver halide during development as hardening prevents the scattering of light which gives infectious development (spreading of silver development beyond the exact image boundaries. As a result of these effects Pyro is capable of more pronounced edge effects than other developers.

Of course, reduced agitation along with dilution are the keys to masterful use of Pyro staining and hardening negatives, and to that end I suggest farther reading of Steve Sherman's article on the subject, "Altering a Negative's Personality: Reduced Agitation Film Processing, at https://unblinkingeye.com/Articles/RASS/rass.html.

Sandy

I fully concur with this. My extensive personal testing last year to find my own optimal semistand and EMA configuration bears this out visibly and beautifully.

[interneg]

That said, it is hardening that results in more precise reduction, which gives Pyro gives more pronounced edge effects than other developers. This is due to the fact that there is much less migration of silver halide during development as hardening prevents the scattering of light which gives infectious development (spreading of silver development beyond the exact image boundaries. As a result of these effects Pyro is capable of more pronounced edge effects than other developers.

In an unhardened emulsion this might be the case. In a vinyl ether hardened emulsion it's going to be questionable at best. What is however known (and can be found in the literature/ patents from the 1970s onwards and hinted at elsewhere) seems to be that Phenidones (better yet, Dimezone-S) can deliver potentially extremely strong development inhibition effects giving the adjacency effects you attribute to Catechol's dye coupler 'stain'. A PQ (or PC or PA) developer with the right ratio of the ingredients with a carbonate buffer should be very readily capable of delivering strong adjacency effects - they optimise in the pH range that carbonate buffers deliver. With modern emulsions, solvency will deliver better sharpness via accessing & releasing Iodide & Bromide (which are regarded in this context as development inhibiting agents) placed in the emulsion(s) explicitly to produce these effects. A great deal of B&W film R&D seems to have concentrated on getting conventional B&W emulsions to deliver something approximating the desirable effects of DIR/ DIAR (and subsequent evolutions - including phenidone releasing variants) couplers in C-41 materials. Most commercial PQ developers (barring a handful like Ilfosol 3) largely seem to have tended to tune down the adjacency effects as double-blind visual testing historically seems to have largely preferred D-76's grain/ sharpness character.

[tundra]

In an unhardened emulsion this might be the case. In a vinyl ether hardened emulsion it's going to be questionable at best. What is however known (and can be found in the literature/ patents from the 1970s onwards and hinted at elsewhere) seems to be that Phenidones (better yet, Dimezone-S) can deliver potentially extremely strong development inhibition effects giving the adjacency effects you attribute to Catechol's dye coupler 'stain'. A PQ (or PC or PA) developer with the right ratio of the ingredients with a carbonate buffer should be very readily capable of delivering strong adjacency effects - they optimise in the pH range that carbonate buffers deliver. With modern emulsions, solvency will deliver better sharpness via accessing & releasing Iodide & Bromide (which are regarded in this context as development inhibiting agents) placed in the emulsion(s) explicitly to produce these effects. A great deal of B&W film R&D seems to have concentrated on getting conventional B&W emulsions to deliver something approximating the desirable effects of DIR/ DIAR (and subsequent evolutions - including phenidone releasing variants) couplers in C-41 materials. Most commercial PQ developers (barring a handful like Ilfosol 3) largely seem to have tended to tune down the adjacency effects as double-blind visual testing historically seems to have largely preferred D-76's grain/ sharpness character.

So, if we stipulate to that, we'd expect to see little- or no pyro-related adjacency (edge/Mackie line) effects. That may be true in theory, I haven't sufficient expertise to comment on the theoretical matters at hand. However, this is what I have seen, in actual fact with real negatives using PMK, and then later Pyrocat-HD, the latter in very dilute, very long development procedure:

1. PMK shows edge effects with some modern films - Tri-X and Agfapan APX 100 leap to mind. I believe both are hardened emulsions.

2. Pyrocat-HD similarly shows edge effects. These are more pronounced with some films (Tri-X, FP4) than others (Agfapan APX 100). It's more pronounced with EMA than semistand in all cases.

3. There's no question that unhardened emulsion seem to love Pyro, though. Efke PL100M, for example, really shows the edge effects and improved acuity of using these developers. I am not sure how Adox CMS 100 II is made, but it seems to like it as well.

If your argument is that a phenidone-based developer could achieve the same/better results with modern films, that may be so, but I've not seen any examples thereof. I have done seminstand with D-23 and highly dilute HC-110 (1:128) and seen some, but not as pronounced such effects.

If you're saying pyro does not have this adjacency effect at all or minimally with modern emulsions, my negatives kindly take umbrage with you.