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B&W slides: Herrman revisited. Pyrocatechin-Metol-Ascorbate 1st developer PMA-R1

Relayer

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Location
Odessa, UA
Format
35mm
Hello

After many experiments with different 1st developers for bw-slides I found something best for me. My goals: high active, phenidone free, fine grain and fog free developer. I'm starting from Herrman fine grain developer. Follow is the stock

Metol 9 g
Pyrocatechin 9 g
Sodium Sulphite 60 g
Sodium Carbonate 60 g
Water 1l

Modified formula of my 1st developer for bw-slides PMA-R1:

Sodium Ascorbate 11g
Metol 10g
Pyrocatechin 10g
Sodium Sulphite 60g
Sodium Carbonate 60g
Borax 14g
Potassium bromide 2g
Potassium thiocyanate 3g
Water 1l

Because I haven't sodium ascorbate I was mix 10g of Ascorbic Acid with 3g of Sodium hydroxide.
Starting dev time 8-10min 21C. Some shots from Ilford P3 200 Surviellance (expired, real ISO ~100) @200 (push+1) 14min 21C 5rotation/1min





 
If you really want an excellent fine grain slide, locate some Kodak Teck Pan and try it. I used it in 120 for b&w slides and the outcomes were so amazing. A local lab at the time did the developing as I was paying the nickel for them to experiment but sadly, I never found out what they finally used but I think it may have only been the Kodak b&w slide developer. Showing the 645 slides with the tonality that Tech Pan could have from processing was better than certain physical activities between consenting adults.. I used a Polaroid projector at the time and always wondered how much better they could have shown if using a better projector and lens. The Polaroid used an Kodak Ektar lens.
 
2nd attempt. same film. but @400. dev time 14min. 21C. agitation 5rotation / 30sec



 
Whats the point of adding Ascorbic acid (turned into sodium ascorbate by strong bases, probably referring to Caffeine developers the 60 gram sodium carbonate in the mix would have been more than enough for that.....).

But whats the point of adding ascorbates and keeping BOTH metol and pyrochatecine? The general idea of using ascorbates have been replacing one or both developing agents....

What you hope to achieve with this mix, that the original didn't already do?
 

Relayer said:
My goals: high active, phenidone free, fine grain and fog free developer
Click to expand...

really this is the fifth version of formula. all otther wasn't not suitable for me. maybe in the next versions I will try to exclude metol/pyrochatecine. but very possible that this decrease activity
 
I think it looks really great from your examples! Keep it as it is and do more work with this combination.
 
I still don't get it, the 5th version of what?

As far as I'm concverned I don't se the point of adding one more developing agent, from 2 to 3.

I only embark on excercises like that to take OUT one dev. agent and replace it with another, there's a limit to what you can do with several of these agents in one and the same litre of water, the more, the less each contribute, since they compete in a manner of speaking.

And without further evidence, its impossible to conclude that there was an improvement, we must see examples of the early and supposedly bad developer, compared to the new and improved.

Besides your formula is incomplete, since you added 3gram NaOH which is a very powerful basic substance, which will make the pH go up very quickly... You only mention that in a sidebar, instead it should be highlighted.

Also I see no big difference between 1. attempt and the 2. what was important here?


To me, if this excercise was important, I would :

1 replace Metol with ascorbic acid, and since ascorbic acid is very soluble, compared to metol I would turn the formula upside down, soda first, then ascorbic acid. This would leave no necissity for NaOH, since NaCO3 does the same thing and there's plenty of it!

I would keep KBr since this removes chemical fogging.

This leaves potassium thicyanate, why that?

Anyways, I would test this, to see if there was any pint in this.

2. Then I would go the other direction and change out pyrocatechin with ascorbic acid, along a similar line of thought, and see if that worked any better.

But just lumping a heap of developing agents into one developer that is supposed to work perfectly well, seems futile.
 
Erik Prestmo said:
I still don't get it, the 5th version of what?
Click to expand...
version of pyrocatechin-metol-ascorbate developer

Erik Prestmo said:
And without further evidence, its impossible to conclude that there was an improvement, we must see examples of the early and supposedly bad developer, compared to the new and improved.
Click to expand...
you really need to see scans with fog, under/overdeveloped etc?

Erik Prestmo said:
Besides your formula is incomplete, since you added 3gram NaOH which is a very powerful basic substance, which will make the pH go up very quickly... You only mention that in a sidebar, instead it should be highlighted.
Click to expand...
10g Ascorbic acid + 3g NaOH = 11g Sodium Ascorbate + H2O

Erik Prestmo said:
Also I see no big difference between 1. attempt and the 2. what was important here?
Click to expand...
push+2 instead push+1, but same dev time

Erik Prestmo said:
This leaves potassium thicyanate, why that?
Click to expand...
potassium thicyanate is required for 1st developer of bw/color slides.

Erik Prestmo said:
But just lumping a heap of developing agents into one developer that is supposed to work perfectly well, seems futile.
Click to expand...
Erik, have you experience with homebrew bw reversal? developers for slide-process have some specifics. I'm present working solution which produce good result. you can use it or not. you can disagree with my formula, but its work. if you need - you can try to improving it replace some components.
 
That ascorbate reaction is dubious at best, because we're taling organic chemistry here.

rarely if ever will organic substances react nearly 1200% as you imply here, more likely 50% - if you're lucky.
I started organic cemistry lab a looong time ago be getting the cofeine out of cofee...... it was a chore.
 
"potassium thicyanate is required for 1st developer of bw/color slides."

Who sold you that?

I checked with my copy of "Wissenschaftliche und Angewandte photographie" Springer verlag, Berlin 1955.

All "diapositiv-verfaren" both film and paper, and all 8 different processes for kinefilm from the big names back then, Ansco, Perutz, Agfa and so on, noone of them mentioned that at all.

But all had varying amounts of potassium bromide and citric acid in them, to keep fog in check I presume.

Absolutely noone mentioned this to be a requirement. I could cite all the recipes, but maybe this is already written in stone?
 
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I don't feel I have to justyfy anything, Alessandro, I'm just telling you how this was done back in the times the professionals did it, and these formulas are bona-fide factory stuff, as reported.

As with a lot of other modern-day cludges, there is a good chance this was over-developed(!)
 
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Erik Prestmo said:
"potassium thicyanate is required for 1st developer of bw/color slides."
Who sold you that?
Absolutely noone mentioned this to be a requirement. I could cite all the recipes, but maybe this is already written in stone?
Click to expand...

check Kodak D-94, ORWO-829. both uses Potassium/Sodium thiocyanate.
good starting point is here
 
Kodak and Orwo, well Orwo wasn't there in 1955, but Kodak didn't. And think of all the amasing quality B/W films (movies) made long before 1955!

Besides, if you didn't know ascorbic acid (ascorbate) already IS a silver halde solvent, that IS the fine grain developer charateristics to this developing agent! All fine grain developers ARE, or show silver halide solvent characteristics, this a basic knowledge.
 
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yes, I know about this property of ascorbate. but Thiocyanate is more strong solvent than ascorbate. if we exclude Thiocyanate - 11g/l of ascorbate can't help us to obtain clear highlights
 
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Ah I looked it up on Wiki....potassium thiocyanate, there was a missing o in there....

formula is KCNS, which goes by the name of Kaliumrhodanid in old german literature, at THAT is there in many of the formulas.

Now what is the purpose of this silver halide solvent here, fine grain or just get rid of some of the silver halides to get a more transparent diapositive?

Also the book mentions that all positive developers are in essence paper developers diluted 1:1 to begin with, before improvements.
They did think in simpler terms back in the day, but if you look at some of the reversal processing done, for instance 16mm film, they did sterling work.

And back when I was thought to work in a darkroom by a now long dead friend, I discovered he made B/W slides on a regular basis, some of it was contact prints on 4x4 glass plates , but he did ordinary films too. And ordinary film = regular Kodak Plus X bought at the local photographers.

I bought kits from the UK back in the 1970's and reversal developed FP3 and later FP4 myself, of course it looked bland compared to Kodachrome!
 
Alessandro Serrao said:
Relayer, you're from Odessa right?
This is OT but one of my dreams come true would be that of making a photo trip to Припять and Чернобыль...
Click to expand...

You'd have to develop the films in a hurry though! and maybe eat the same shit we feed our sheep after spending the summer in our mountains, we had a bad fallout here back in 1985.......there was restrictions on eating mutton for a year or two afterwards...
 
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..dont let 'em get you down. Sometime we dont know why agents do the things they do to film. This is what experimenting is all about. Study the agents being used. Use the scene [film/chem] like an artist palette.

dw



 
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