Developers, potassium/sodium hydroxide, and reversal processing

pkr1979 · Feb 20, 2022

Hi all,

Ive been experimenting with different developers for black and white reversal. Ive tried developers from Kodak, Ilford and Tetenal, and also mixing my own from powder. Ive been trying with different films to see what kind of results Id get.

One of the best results I got was with Ilford PQ and Tmax400 (a bit grainy). Ive been trying to get similar results using D19 (with Tmax400) but its not quite as good.

With PQ it was not necessary to use a silver solvent. With D19 first developer times are getting pretty long without thiocyanate, with thiocyanate (2g/L) I really dont like the midtones.

So, as far as I can understand, this means that PQ contains something D19 does not… One of the things that differs in PQ compared to D19, is that PQ uses Potassium carbonate and Sodium or Potassium Hydroxide instead of Sodium Carbonate (https://www.photrio.com/forum/threa...s-ilford-pq-universal-paper-developers.63236/)

Ive also come to understand that caustic developers are handy for reversal (https://www.photrio.com/forum/threads/reversal-processing-with-d-11.128367/), meaning it should contain Sodium Hydroxide in the formula.

So I guess my question is something like this…

- Is it likely that adding potassium or sodium hydroxide to the D19 would result in a developer that would provide similar results as with PQ?

- If so, does it matter if its potassium or sodium hydroxide? I already got sodium hydroxide.

- Also, how much would be needed? And what other parts of the formula would have to be adjusted (ie switch from sodium carbonate to potassium carbonate, maybe this is necessary if one uses potassium hydroxide instead… or not)?

Cheers
Peter

Raghu Kuvempunagar · Feb 21, 2022

@pkr1979: In my limited experience trying to reversal process TMax 400, I found it difficult to get good results without Thiocyanate in the first developer. However, you might want to take a look at "Commercially Available First Developer Containing Hydroquinone" in this Agfa patent which uses a development accelerator but no halide solvent. pH ~10.2.

Philippe-Georges · Feb 21, 2022

Agfa advised to add "Kaliumthiocyanaat" (I don't know the correct name in English) to Neutol liquid (the same as Ilford's PQ universal?) as the first developer in their Dia-Direct process.
I add in appendix the original document, dating from 1977, I got from AGFA long time ago. This was the basis for the process I used to reversal process ILFORD DELTA film which gave very good results (as you can see here: http://www.photoeil.be/books/dieter-roth.html).
The documents are in Flemish/Dutch, please do forgive me not to be able to translate these...

Raghu Kuvempunagar · Feb 21, 2022

Philippe-Georges said:
Agfa advised to add "Kaliumthiocyanaat" (I don't know the correct name in English) to Neutol liquid (the same as Ilford's PQ universal?) as the first developer in their Dia-Direct process.

This is Potassium thiocyanate.

Ian Grant · Feb 21, 2022

PQ Universal is a PQ version of Ilford ID-20 which was an MQ powder developer, Ilford sold ID-20 PQ for a short time, but there were complaints that image colour was varying with use, tones becoming warmer as bromide built up. as a result they reformulated as a liquid concentrate (PQ Universal) adding Benzotriazole. To achieve a reasonable concentration, the Sodium Carbonate was replaced by more soluble Potassium Carbonate and some Sodium Hydroxide to maintain the same pH.

So the simple answer is adding Sodium or Potassium Hydroxide to D19 will not achieve what you are after, D19 was replaced by D19b which is identical to Ilford ID-19. I mixed the PQ version of Ilford ID-19 which us ID-72, I tried it as a print developer but was disappointed with the results.

The Agfa formulae above uses Agfa Neutol NE which will be quite close to PQ Universal. Neutol WA is almost identical to the Ilford ID-78 concentrate I mix, which is itself a minor variation of ID062.{Q Universal.

There's some Reversal fomulae here.

Ian

Raghu Kuvempunagar · Feb 21, 2022

Ian Grant said:
The Agfa formulae above uses Agfa Neutol NE which will be quite close to PQ Universal.

The crucial difference being the presence of a supposed development accelerator in the Agfa formula. Agfa first developer uses PEG which according to @Lachlan Young is the development accelerator that aids in clearing the highlights without needing a halide solvent.

TMax 400 is a difficult film to reverse without a halide solvent like thiocyanate, at least at box speed, no matter what first developer is used. I would use HP5+ any day over Tmax 400 for reversal.

[Edit: noticed that DR5 has the following to say on TMax 400:
"The normal iso for this film in dr5 is 125iso. TMAX400 can not be run at 400. TMY is easier to work with if shot between 32 & 125iso."]

Lachlan Young · Feb 21, 2022

Raghu Kuvempunagar said:
The crucial difference being the presence of a supposed development accelerator in the Agfa formula. Agfa first developer uses PEG which according to @Lachlan Young is the development accelerator that aids in clearing the highlights without needing a halide solvent.

TMax 400 is a difficult film to reverse without a halide solvent like thiocyanate, at least at box speed, no matter what first developer is used. I would use HP5+ any day over Tmax 400 for reversal.

[Edit: noticed that DR5 has the following to say on TMax 400:
"The normal iso for this film in dr5 is 125iso. TMAX400 can not be run at 400. TMY is easier to work with if shot between 32 & 125iso."]

PEG isn't 'supposed' - it's a known development accelerator (Ron/ PE described it explicitly as such) - along with a list of other polyglycols - and the Agfa Scala patent disclosed first developer seems to be very low solvent and engineered to actively prevent development inhibition (very low solvency, no phenidones, MQ balance & pH all point to this - note too that the use of Metol in the 1990s vis-a-vis the recommendation of Neutol (which is PQ) in the 1970s tallies with the emergence of the understanding of the role the Phenidones can play in development inhibition) - and the specific choice of sequestrants may also play a role. It was/ is capable of dealing with TMY-II and Delta 400 without issues & with what seems to be proper speed utilisation/ Dmax. With Thiocyanate or high levels (50g/L+) of sulphite you may well end up fighting a battle between getting sufficient access to the silver & sufficient density before the inhibitory byproducts & silver solvency of these components kicks in - with a low solvency first developer & a gelatin swelling development accelerator, you may have more of a chance for getting good reversals with emulsions that are intended to be more solvency sensitive (to enhance sharpness, control density etc in negative processes).

Raghu Kuvempunagar · Feb 21, 2022

Lachlan Young said:
note too that the use of Metol in the 1990s vis-a-vis the recommendation of Neutol (which is PQ) in the 1970s tallies with the emergence of the understanding of the role the Phenidones can play in development inhibition) - and the specific choice of sequestrants may also play a role.

Interestingly, with Scala reversal kit, @ADOX Fotoimpex seems to have gone back to PQ first developer.

pkr1979 · Feb 22, 2022

Thanks for getting back to me all of you - much appreciated. @Lachlan Young is a substantial amount of sulfite only an issue with thiocyanate, or either way? I assume this is for films like Tmax400 and not Tri-X.

Ian Grant · Feb 22, 2022

Raghu Kuvempunagar said:
The crucial difference being the presence of a supposed development accelerator in the Agfa formula. Agfa first developer uses PEG which according to @Lachlan Young is the development accelerator that aids in clearing the highlights without needing a halide solvent.

TMax 400 is a difficult film to reverse without a halide solvent like thiocyanate, at least at box speed, no matter what first developer is used. I would use HP5+ any day over Tmax 400 for reversal.

[Edit: noticed that DR5 has the following to say on TMax 400:
"The normal iso for this film in dr5 is 125iso. TMAX400 can not be run at 400. TMY is easier to work with if shot between 32 & 125iso."]

Commercial developers get reformulated. Neutol NE didn't contain PEG back in 1977. PEG is used in developers to aid longevity, as it helps prevent oxidation of developing agents in concentrates, but it's long been known that Glycols can be beneficial, Agfa discovered before WWII that one long chain Glycol added to Rodinal as a wetting agent had a surprising effect as a developer accelerant. It's in a Patent, which I have referenced here in the past many years ago

Sometimes these Glycols are very weak developing agents in their own right, before WWII both Ilford and Kodak used a very low level of Pyrogallol in their commercial MQ replenished deep tank developers, technically it was an oxygen scavenger.

Ian

Raghu Kuvempunagar · Feb 22, 2022

Ian Grant said:
Commercial developers get reformulated. Neutol NE didn't contain PEG back in 1977. PEG is used in developers to aid longevity, as it helps prevent oxidation of developing agents in concentrates, but it's long been known that Glycols can be beneficial, Agfa discovered before WWII that one long chain Glycol added to Rodinal as a wetting agent had a surprising effect as a developer accelerant. It's in a Patent, which I have referenced here in the past many years ago

Sometimes these Glycols are very weak developing agents in their own right, before WWII both Ilford and Kodak used a very low level of Pyrogallol in their commercial MQ replenished deep tank developers, technically it was an oxygen scavenger.

Thanks for the valuable information Ian. Typically what quantity of Glycols is needed per liter of developer for them to aid longevity of the developer and also act as developer accelerator?

pkr1979 · Feb 22, 2022

Whats the difference between D11 and D19? I mean, I can read the differences in the recipes obviously, but what are they in terms of practicalities and results?

Ian Grant · Feb 22, 2022

Lachlan Young said:
PEG isn't 'supposed' - it's a known development accelerator (Ron/ PE described it explicitly as such) - along with a list of other polyglycols - and the Agfa Scala patent disclosed first developer seems to be very low solvent and engineered to actively prevent development inhibition (very low solvency, no phenidones, MQ balance & pH all point to this - note too that the use of Metol in the 1990s vis-a-vis the recommendation of Neutol (which is PQ) in the 1970s tallies with the emergence of the understanding of the role the Phenidones can play in development inhibition) - and the specific choice of sequestrants may also play a role. It was/ is capable of dealing with TMY-II and Delta 400 without issues & with what seems to be proper speed utilisation/ Dmax. With Thiocyanate or high levels (50g/L+) of sulphite you may well end up fighting a battle between getting sufficient access to the silver & sufficient density before the inhibitory byproducts & silver solvency of these components kicks in - with a low solvency first developer & a gelatin swelling development accelerator, you may have more of a chance for getting good reversals with emulsions that are intended to be more solvency sensitive (to enhance sharpness, control density etc in negative processes).

There was a time when Agfa sold both Neutol MQ powder developer and Neutol PQ liquid developers. When I first used Neutol WA around 1987 both versions were available, the PQ version gave slightly warmer tones, the other powder versions had I think been dropped.

Ian

Philippe-Georges · Feb 22, 2022

pkr1979 said:
Whats the difference between D11 and D19? I mean, I can read the differences in the recipes obviously, but what are they in terms of practicalities and results?

I used to process Kodak Technical pan in D19 if I was reproducing text or drawings needing a few midrange tonalities, or text slides for projection, otherwise it was developed in Technidol LC for more mid tones, but it stayed rather high contrasty. I know of a colleague, at the time, making nice portraits on Technical Pan film processed in Technidol LC.
I always wondered if Technidol LC was close to D19 in the way it was not that 'strong' working, but I really don't know for sure...

Ian Grant · Feb 22, 2022

pkr1979 said:
Whats the difference between D11 and D19? I mean, I can read the differences in the recipes obviously, but what are they in terms of practicalities and results?

D11 is a high contrast film or plate developer, D19 is a rapid film or plate developer.

Ian

pkr1979 · Feb 22, 2022

Ian Grant said:
D11 is a high contrast film or plate developer, D19 is a rapid film or plate developer.

Ian

Which means (for reversal as well?) that D19 will develop film faster then D11? But at what cost... contrast I assume, but what else? Tonality? Will D19 be grainier?

Ian Grant · Feb 22, 2022

It's not so simple, D11 has a guide dev time of 5 minutes, D19 6 mins, both at 20ºC. I did some research on reversal processing for a London lab a few years ago, I came up with a very practical process, but there wasn't the money to test it with all films.

The reality is you need to fine tune the reversal; process for each film, that might be first development time and sometimes the level of Thiocyanate. David of dR5 has mentioned numerous times that he varied the first development time for different films and also if shot at different EI's.

Some reversal processes of B&W cine film actually use the re-exposure light intensity.time as a control, and second/redevelopment time has been used as well.

Ian

Lachlan Young · Feb 22, 2022

pkr1979 said:
is a substantial amount of sulfite only an issue with thiocyanate, or either way?

Either way - potentially. I have a suspicion that the level of sulphite is high enough in the Kodak D-11 and D-19 formulae that it may (probably?) cause issues.

pkr1979 said:
I assume this is for films like Tmax400 and not Tri-X.

Difficult to say with certainty - it will likely depend a great deal on iodide quantity/ placement in the emulsions, relative to the intended effects in terms of sharpness effects, highlight density etc in a moderately solvent negative developer. Consider it this way - by all accounts Scala 200x was essentially just APX100 coated at a reportedly higher level of Ag/M2 (for improved reversal performance) - which has characteristics in negative developers indicative of inhibition effects that would not be desirable in reversal development.

Ian Grant said:
Sometimes these Glycols are very weak developing agents in their own right, before WWII both Ilford and Kodak used a very low level of Pyrogallol in their commercial MQ replenished deep tank developers, technically it was an oxygen scavenger.

Pyrogallol is structurally rather different from a polyglycol - from recall, pyrogallol is Catechol with an extra hydroxyl group.

Ian Grant said:
There was a time when Agfa sold both Neutol MQ powder developer and Neutol PQ liquid developers. When I first used Neutol WA around 1987 both versions were available, the PQ version gave slightly warmer tones, the other powder versions had I think been dropped.

It would make sense that the inhibition characteristics of Phenidones might contribute to slightly warmer tones - if the developer is set up to maximise this. I suspect that it may have been Ilford basic research (en route to Microphen) that might have found the inhibition effects - and then the rest of the industry picked up on this through the 1970s - and I should have made it clearer that because the Agfa-Gevaert letter upthread refers to the liquid Neutol NE, that it was the PQ variant I was referring to.

Raghu Kuvempunagar said:
Typically what quantity of Glycols is needed per liter of developer for them to aid longevity of the developer and also act as developer accelerator?

You'd need to find this experimentally. Probably not a lot - and molecular weights may matter quite a bit. You may also find that gelatin swell regulation is necessary (from recall, the Agfa Scala FD formulae appears to suggest the intentional formation of in-situ sodium sulphate - rather than adding it as a discreet ingredient). It's plausible too that some film emulsions use polyglycols (or similar) to effect development acceleration (from recall, Neopan 1600 was described as effectively being a 400 speed emulsion + incorporated development accelerator).

Philippe-Georges · Feb 23, 2022

Ian Grant said:
D11 is a high contrast film or plate developer, D19 is a rapid film or plate developer.

Ian

D19 was popular for EMS and X-ray materials in scientific research.
D11 was more in use for processing copy film, a higher contrast developer indeed.

Ian Grant · Feb 23, 2022

Lachlan Young said:
It would make sense that the inhibition characteristics of Phenidones might contribute to slightly warmer tones - if the developer is set up to maximise this. I suspect that it may have been Ilford basic research (en route to Microphen) that might have found the inhibition effects - and then the rest of the industry picked up on this through the 1970s - and I should have made it clearer that because the Agfa-Gevaert letter upthread refers to the liquid Neutol NE, that it was the PQ variant I was referring to.

Accidental discoveries. The benefits of Phenidone over Metol in warm tone developers came after commercial customer complaints about colour tone shift s (towards warmer) as Bromide built up in pre-packaged ID20 PQ which had replaced ID-20 (MQ). This was exploited by adding additional Bromide to ID-20 PQ and a marginal increase in Carbonate and published and sold as ID-78. Many years later ID-78 was reformulated as a liquid concentrate.

Microphen was a spin off from the research that lead to Autophen, also known as the Axford-Kendall PQ Fine Grain Developer. Autophen was a replenished photo-finishing developer, a PQ variant of D76/ID-11, with two different replenishers for bleed and topping up. Unlike ID-11/D76 Autophen was not affected by Bromide build up or prone to collapse. I think your use of the word inhibited is [problematic, Metol activity is inhibited by Bromide build up, in contrast Phenidone isn't affected at levels 8 to 10 times higher. Most of the research for Autophen was into developer exhaustion and Bromide build up, as well as buffering, so that replenishment was fine tuned and more exact, During research it was noticed that PQ variants of ID-11 gave a slight speed increase, but it was also known that MQ developers like Agfa 44 (Agfa Ansco 17) and Adox Borax MQ gave a slight speed increase compared to ID-11/D76 due mostly to the slightly lower level of Sodium Sulphite So after Autophen they worked on enhancing the effective film speed of a PQ developer resulting in ID-68, Microphen.

Ian

pkr1979 · Feb 23, 2022

Thanks again all

Lachlan Young · Feb 24, 2022

Ian Grant said:
Accidental discoveries. The benefits of Phenidone over Metol in warm tone developers came after commercial customer complaints about colour tone shift s (towards warmer) as Bromide built up in pre-packaged ID20 PQ which had replaced ID-20 (MQ). This was exploited by adding additional Bromide to ID-20 PQ and a marginal increase in Carbonate and published and sold as ID-78. Many years later ID-78 was reformulated as a liquid concentrate.

Microphen was a spin off from the research that lead to Autophen, also known as the Axford-Kendall PQ Fine Grain Developer. Autophen was a replenished photo-finishing developer, a PQ variant of D76/ID-11, with two different replenishers for bleed and topping up. Unlike ID-11/D76 Autophen was not affected by Bromide build up or prone to collapse. I think your use of the word inhibited is [problematic, Metol activity is inhibited by Bromide build up, in contrast Phenidone isn't affected at levels 8 to 10 times higher. Most of the research for Autophen was into developer exhaustion and Bromide build up, as well as buffering, so that replenishment was fine tuned and more exact, During research it was noticed that PQ variants of ID-11 gave a slight speed increase, but it was also known that MQ developers like Agfa 44 (Agfa Ansco 17) and Adox Borax MQ gave a slight speed increase compared to ID-11/D76 due mostly to the slightly lower level of Sodium Sulphite So after Autophen they worked on enhancing the effective film speed of a PQ developer resulting in ID-68, Microphen.

Ian

What you describe is what Ilford was willing to disclose publicly in the 50's/ 60's. Phenidone derived development inhibition behaviour doesn't seem to start getting hinted at until the 1970s & eventually is regarded as 'safe' enough (i.e. all the main players in the industry clearly seem to have known about it) to disclose in papers/ theses in the early 1980s. It's a characteristic that's visually and microdensitometrically observable at the most extreme level in things like POTA. Beyond the effects you outline above, Metol seems to produce adjacency effects via exhaustion (thus adding HQ & similar, either at superadditive - or just below (a de-facto & observable apparently 'electron-pump' type effect - if not designed as such) switches this off) while the Phenidones' byproducts seem to act as development inhibitors (not dissimilarly to the releases of development byproducts (Br, I) from the emulsion(s)) and can be modulated through relative levels of P:Q & pH - however, this sharpness improvement can (obviously) also increase the apparent granularity.

Raghu Kuvempunagar · Feb 24, 2022

Lachlan Young said:
Beyond the effects you outline above, Metol seems to produce adjacency effects via exhaustion (thus adding HQ & similar, either at superadditive - or just below (a de-facto & observable apparently 'electron-pump' type effect - if not designed as such) switches this off) while the Phenidones' byproducts seem to act as development inhibitors (not dissimilarly to the releases of development byproducts (Br, I) from the emulsion(s)) and can be modulated through relative levels of P:Q & pH - however, this sharpness improvement can (obviously) also increase the apparent granularity.

Just curious. What is the significance of all this to reversal processing as the negative silver image is any way going to be bleached out? Do edge effects in the negative silver image translate into edge effects in the positive image? Ditto with fine grain.

Ian Grant · Feb 24, 2022

Thanks Lachlan for clarifying what you meant, the developer by-products can also be a localised accelerator depending on the various factors you mention and also the level of Sulphite. I think you may be a decade or two out as Axford and Kendall, and James, published papers on Phenidone oxidation much earlier, James paper was 1962.

Ian

Lachlan Young · Feb 24, 2022

Raghu Kuvempunagar said:
Just curious. What is the significance of all this to reversal processing as the negative silver image is any way going to be bleached out? Do edge effects in the negative silver image translate into edge effects in the positive image? Ditto with fine grain.

It's not the edge effects per se (the high contrast of a transparency makes it look 'sharp' when viewed directly - even if the outright sharpness isn't as good as a negative, which has implications more in terms of reproduction/ printing rather than direct viewing), but that they are formed by development inhibition - and because you want to access and develop all the silver for reversal, you want/ need minimal development inhibition when dealing with relatively thin B&W emulsion structures (from recall APX 100/ Scala 200x had a 7 µm emulsion layer, RSX100 was 25 µm) that are largely designed to be highly receptive to developer solvency - in other words, it's much cheaper to design a specific developer & use a small modification of an extant neg working stock, than to design and make a reversal specific B&W emulsion!

Developers, potassium/sodium hydroxide, and reversal processing

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