Advice on my Two Bath Developer

relistan · May 12, 2021

Donald Qualls said:
You'll still get ascorbate. In fact, you'll get ascorbate in the presence of any dissolved ions in sufficient quantity (add table salt, you'll get an equilibrium mix of Na+, Cl-, and ascorbic acid <-> sodium ascorbate and HCl). Ascorbate forms in any conditions that allow the ascorbic acid to ionize (assuming you didn't just start with sodium ascorbate for pH reasons).

Thank you! Very helpful

Raghu Kuvempunagar said:
Alan,

When you tested Relayer's PC 2 bath developer, did you observe any development in the first bath? I could be wrong but pH of ~7 might enable some development at least when the agitation is continuous. I believe Phenidone's pH threshold is somewhere in the ballpark.

@relistan: did you notice any developing in part A of your developer which has a pH similar to Relayer?

Phenidone is active above 6.6 from what I had read in Haist. 2B-4 is pH 6.8 and I let it sit for ten minutes to test when I first made it. There was a very tiny amount of development after ten minutes. At five there was effectively none.

Alan Johnson · May 12, 2021

Raghu Kuvempunagar said:
Alan,

When you tested Relayer's PC 2 bath developer, did you observe any development in the first bath? I could be wrong but pH of ~7 might enable some development at least when the agitation is continuous. I believe Phenidone's pH threshold is somewhere in the ballpark.

@relistan: did you notice any developing in part A of your developer which has a pH similar to Relayer?

Yes, there was a faint image at this pH, see post 128. I did not measure the pH but it was probably pretty close to Borax, 9.2 IIRC.
I suspect there may be problems from carry over much above this pH, but IMO that still leaves the option to change part A.
relistan mentioned , if I understood, that there might be a problem with carry over PC accumulating in part B. All I can say is that Relayer never mentioned it so hope for the best.
Edit, sorry I misread the question and answered for the second bath. I never checked for development in the first bath.

Raghu Kuvempunagar · May 13, 2021

Alan Johnson said:
The key factor IMO is whether the final formula turns out to be any better than the established Barry Thornton 2-bath developer.

Alan, is there any data on the strength of superadditivity of Phenidone and Ascorbic acid at various pH that you can share?

Alan Johnson · May 13, 2021

Raghu Kuvempunagar said:
Alan, is there any data on the strength of superadditivity of Phenidone and Ascorbic acid at various pH that you can share?

I don't think that such data is publicly available and when I asked what happened to Kodak research lab documents when they effectively shut down, nobody knew.
From 16 years ago , Ryuji was probably the leading expert on 2-bath ascorbate:
https://www.photrio.com/forum/threads/vitamin-c-in-divided-developer.11654/
In post 2 he says the pH in part A should be 7.5 to 8.3 and in post 43 he suggests to avoid phosphates, but I think that would only apply to part A.
The tinkering I did was before the carry over problem was known and should be ignored.

Raghu Kuvempunagar · May 13, 2021

Alan Johnson said:
From 16 years ago , Ryuji was probably the leading expert on 2-bath ascorbate:
https://www.photrio.com/forum/threads/vitamin-c-in-divided-developer.11654/
In post 2 he says the pH in part A should be 7.5 to 8.3

Wouldn't there be some development happening in the first bath at that pH range? This would depend on the concentration of the developing agents in part A of course, but both Relayer's and Karl's developers have a good amount of Ascorbic Acid plus appropriate amount of Phenidone in part A.

Raghu Kuvempunagar · May 13, 2021

Raghu Kuvempunagar said:
Wouldn't there be some development happening in the first bath at that pH range? This would depend on the concentration of the developing agents in part A of course, but both Relayer's and Karl's developers have a good amount of Ascorbic Acid plus appropriate amount of Phenidone in part A.

Ryuji has an answer for my question further down in the thread you shared!

Ryuji said:
Contrary to what's written in common darkroom bibles, two bath development is not like mixing bath A and bath B in the emulsion layer when the film is transported. I do not know of a successful two-bath developer where film is not developed at all in bath A.

relistan · May 13, 2021

Raghu Kuvempunagar said:
Ryuji has an answer for my question further down in the thread you shared!

Haha, I love this because this was my previous experience also. I have gone the route that I have gone in part because of much earlier feedback on this thread. But this was from my first post:

relistan said:
The general theory is that for a two bath developer, substantially no development happens in the first bath and then development starts in the second. I know from experience with various 2 baths that that's just not reality. If you want full film speed, you always have and and need to have a little development in the first bath. The emulsion (at least modern emulsion) just doesn't soak up enough developer to develop only from what was absorbed. So, I decided to try a PQ developer, knowing that phenidone will start development even in mildly acidic solutions.

Attempting to prevent any development in A is the reason for the high concentration of developing agents in B. Which makes the carryover worse. So maybe I should attempt to cut it in half and raise the pH of A to be more like 2B-1, as a more drastic approach.

Raghu Kuvempunagar · May 13, 2021

There's at least one 2-bath developer of some repute that does no development in the first bath - divided Pyrocat. However, I did notice carryover problem with this developer but I used a higher dilution than what's recommended by Sandy King which is 1:10.

Alan Johnson · May 13, 2021

Re the pH of the first bath PC that has been tested :
LOMAD - 6.8 http://ascorbate-developers.blogspot.com/2012/02/lomad-diafine-clone.html
Relayer - not known
Ryuji - 7.5 to 8.3

Raghu Kuvempunagar · May 13, 2021

michael_r said:
Why not simply have a reusable, weakly acidic bath A and plain alkali one-shot bath B? Easy to keep a plain alkali stock around and mix more when you run out.

Would a process like the following yield something useful?

1. Take any PC or MC print developer formula (e.g. DS-14). Prepare the developer stock minus carbonate. Acidify it just enough to keep the pH weakly acidic.
2. Choose the pH of one-shot alkali bath, between 8.3 - 11.5. Prepare the alkali solution using appropriate amounts of Sodium Carbonate and Sodium Bicarbonate.
3. Find out the dilution of the developer stock at which crossover doesn't cause a problem for the chosen alkali bath.
4. Test this dilution on film and find out if it gives the speed and contrast you're looking for.
5. If answer to 4 is no then go to step 2 and pick a different pH. If the answer to 4 is yes then fine tune the developer formula around this dilution and pH.

relistan · May 13, 2021

michael_r said:
Why not simply have a reusable, weakly acidic bath A and plain alkali one-shot bath B? Easy to keep a plain alkali stock around and mix more when you run out.

The one-shot B was a thing I was starting to think about this morning as well. I was actually thinking a B concentrate (in water) that you could mix like 4:1 or something and keep around without remixing for awhile. This prevents the buildup of carryover that I think I am seeing. And 1 liter of concentrate to be mixed 4:1 should get like 15-16 films out of your bath A which seems about right.

I am still not convinced that the acidic A is the right route though. Because you need to have a high concentration of developing agents to handle thinner emulsions. There is a tradeoff between supporting thin emulsions and films with higher diffusion rates, and thicker films or slower diffusion rates. You could probably make one that supports a range of them, but I am not sure you could make a universal developer. That being said, I'd be happy with a developer that supports Delta 100, ADOX Silvermax, Fomapan 100, and HP5+, my main films. Even in that list they are quite different, though. Nonetheless I will try some this approach some more to see what I can manage.

relistan · May 13, 2021

Raghu Kuvempunagar said:
Would a process like the following yield something useful?

1. Take any PC or MC print developer formula (e.g. DS-14). Prepare the developer stock minus carbonate. Acidify it just enough to keep the pH weakly acidic.
2. Choose the pH of one-shot alkali bath, between 8.3 - 11.5. Prepare the alkali solution using appropriate amounts of Sodium Carbonate and Sodium Bicarbonate.
3. Find out the dilution of the developer stock at which crossover doesn't cause a problem for the chosen alkali bath.
4. Test this dilution on film and find out if it gives the speed and contrast you're looking for.
5. If answer to 4 is no then go to step 2 and pick a different pH. If the answer to 4 is yes then fine tune the developer formula around this dilution and pH.

This is a good approach. My approach to 2B-1 was starting with the phenidone and hydroquinone ratio from ID-67 concentrate. I did find that having sulfite in B makes a difference to grain though. But I would guess that you can compensate for that with more in A.

relistan · May 13, 2021

Alan Johnson said:
Re the pH of the first bath PC that has been tested :
LOMAD - 6.8 http://ascorbate-developers.blogspot.com/2012/02/lomad-diafine-clone.html
Relayer - not known
Ryuji - 7.5 to 8.3

Very interesting. I found this interesting discussion about LOMAD, where Jay DeFehr says not to re-use B more than a couple of times:
"I don't recommend re-using the B solution in this type of developer more than once or twice, at most, because developing agents build up and it becomes a more or less standard developer instead of an alkali bath."

And this, confirming what I think is part of what is happening with 2B-4:
"The 12ml figure is irrelevant, except for the first film developed, because we're talking about accumulation. At some point, due to accumulation of bath A into bath B, bath B begins to develop film on its own. This is what I've been telling you, and what you've proven by your test. This is not how we want a 2-bath developer to behave. It's best to dump the alkali bath after a few films ( 2-3, not 15-20). To make your B bath economical, you'll have to leave out the sulfite, which will make your negatives sharper, and reduce fog, so you won't need the KBr, either."

And there he makes the point about sulfite in B. I have seen essentially no fog, but I'm using quite a low amount of sulfite.

Worth reading the thread, despite the testy nature of the discussion.

Donald Qualls · May 13, 2021

relistan said:
I'd be happy with a developer that supports Delta 100, ADOX Silvermax, Fomapan 100, and HP5+, my main films.

I guess my question here is why do you need a 2-bath? D-76/ID-11, Xtol/DD-X/XT-3/EcoPro, HC-110/Ilfotec HC etc. all do a find job with each of those films. Sure, it's cool to not have to worry about temperature, and to be able to put all of the above in the same tank at the same time -- but at least for me, it's the same issue as with Diafine -- you'll get whatever development you get, no chance to adjust the process like we routinely do with conventional developers.

relistan · May 13, 2021

Donald Qualls said:
I guess my question here is why do you need a 2-bath? D-76/ID-11, Xtol/DD-X/XT-3/EcoPro, HC-110/Ilfotec HC etc. all do a find job with each of those films. Sure, it's cool to not have to worry about temperature, and to be able to put all of the above in the same tank at the same time -- but at least for me, it's the same issue as with Diafine -- you'll get whatever development you get, no chance to adjust the process like we routinely do with conventional developers.

You could ask the same question about why anyone does anything new. I mean, we could all just use D-76 and be done with it. But, the exercise is for fun, for learning, and because I like the results that I have been obtaining. I like the compensating effect and that if I had some shots where my exposure was not perfect, they will still come out OK. I regularly use XTOL (now XT-3) and in the past I have regularly used Rodinal, R09, D-76, D-23, HC-110, Diafine, Barry Thornton's two bath, various divided D-76 versions, Stoeckler two bath, and PC-Glycol. But part of the fun of making your own developer is you can make one that gets you the results you like for your films. And you learn something along the way.

Raghu Kuvempunagar · May 14, 2021

Donald Qualls said:
no chance to adjust the process like we routinely do with conventional developers.

Not quite true at least with 2-bath developers of yore. Here's data for Meritol-Caustic 2-bath developer and you can see it is not one size fits all situation with this developer.

relistan · May 14, 2021

Raghu Kuvempunagar said:
Not quite true at least with 2-bath developers of yore. Here's data for Meritol-Caustic 2-bath developer and you can see it is not one size fits all situation with this developer.

View attachment 274449

Interesting reference and a good point, I didn't respond to this part either: with divided developers like 2B-1 vs "true" two bath developers, you have as much control as you want by changing dev time in A.

I'm starting to think that the right approach for an acidic bath A might be a one-shot A concentrate and a one-shot B concentrate. That would let you have different concentrations of A for different films, and no residual carryover issue in B.

relistan · May 14, 2021

Using @Raghu Kuvempunagar 's numbers from earlier in the thread this is a comparison of carryover amounts for Relayer's PC 2 bath, and my 2B-4 vs ascorbate developers PC-Glycol (Gainer), PG-110B (Jay DeFehr):

Carryover Amount vs Ascorbate Developers

Developer	Ascorbic/Ascorbate	Phenidone
PC-Glycol	0.6g	0.015g
Relayer	0.2g	0.004g
PG-110B	0.3g	0.03g
2B-4	0.24g	0.01g

It's pretty evident that 2B-4 has too much phenidone to work here. But as Raghu said, it seems like Relayer's two bath will probably develop film in B.

relistan · May 14, 2021

michael_r said:
Hi Relistan,

Regarding one-shot A and B concentrates, sounds perfectly reasonable to me. This is how most staining developers (for example, but for different reasons) are packaged. Of course those are mixed into one-shot single solutions but you get the idea.

Right, that's true. Makes sense.

michael_r said:
I would caution against putting too much emphasis on comparisons with developers by the other names listed above. None of them ever offered any kind of objective analyses of their various concoctions. They didn’t consider emulsion speed, characteristic curves or other criteria, so I would not put too much stock in any of them.

This is a good point. The idea was to just reference some developers that we know can developer film in low concentrations to compare the carryover against them to see if there will be an issue. This was Raghu's idea and I think it's useful. I made it a table and added 2B-4 for clarity.

Meanwhile I did some testing and found:

Residual carry over is a big issue. Several days later, without any added bath A, 2B-4's bath B is still a pretty good film developer.
Cutting 2B-4 concentration in half makes a pretty crap developer. I first tried with just Borax bath B, but then also with 3% TSP bath B as well. No good.
Without the sulfite, the TSP bath B causes uneven development
2B-4 bath A is 1.5 months old and HEDP seems to be preserving it fine so far (in tap water)

Tomorrow I will try out 2B-4's A with a borax B again, looking to come up with a one-shot bath B as a starting point.

EDIT: Looking at my notes, one of my earlier attempts (not posted) was not far off Relayer's developer in terms of ratios and amounts, but I did not like how it looked (grainy, too much contrast) and negatives were a bit thin. This was the formula for A:

Sodium sulfite 35g
Phenidone 0.25g
Potassium bromide 0.2g
Ascorbic acid 12g
Etidronic Acid 5ml

Seems like reducing AA instead of adding phenidone might be the better approach in terms of concentration of developing agents being present.

Alan Johnson · May 14, 2021

I believe it is usually considered that sulfite does not have much solvent effect below 45g/L and that its solvent effect peaks at about 70-80g/L.
Relayer has 65g/L in part A and 65g/L in part B. Diafine substitute has 35g/L in part A and 65 g/L in part B.
Going with 35g/L in part A and zero in part B your developer would always be grainy.
But replacing part B with 65 g/L sulfite in it every 2 or 3 uses is going to make it relatively more costly.
So the local cost of sulfite would need to be considered if you want a fine grain developer, but generally it is pretty cheap.

relistan · May 14, 2021

Alan Johnson said:
I believe it is usually considered that sulfite does not have much solvent effect below 45g/L and that its solvent effect peaks at about 70-80g/L.
Relayer has 65g/L in part A and 65g/L in part B. Diafine substitute has 35g/L in part A and 65 g/L in part B.
Going with 35g/L in part A and zero in part B your developer would always be grainy.
But replacing part B with 65 g/L sulfite in it every 2 or 3 uses is going to make it relatively more costly.
So the local cost of sulfite would need to be considered if you want a fine grain developer, but generally it is pretty cheap.

Thanks, Alan. Yeah, I have always had 35g in bath B as well, which combines with the 35g in bath A. Which makes me wonder if sulfite is also slowly building up in B.

I was trying to do some calculating on a concentrate A that you could use to make one shot bath A from. I am able to find a lot of solubility data for individual chemicals, but I am not able to figure out how ascorbic acid and phenidone will do in a very thick sodium sulfite/metabisulfite solution. I suspect not that great. I wrote a little program so I can easily change around numbers and get new calculations. I am looking at trying to do something like this:

--------------------------------------------------------------------------------
Bath A Stock
--------------------------------------------------------------------------------
Stock ml: 330.0
Stock ml per film: 30.0
Number of films: 11.0

Carryover: 20ml per film

P/C Ratio: 27
Phenidone: 0.99g
Ascorbic Acid: 26.73g
Sodium Sulfite: 82.5g
--------------------------------------------------------------------------------
Working Solution
--------------------------------------------------------------------------------
Working ml per film: 300.0

Phenidone in bath: 0.09g
Phenidone in film: 0.006g

Ascorbic Acid in bath: 2.43g
Ascorbic Acid in film: 0.162g

Sulfite in bath: 7.5g
Sulfite in film: 0.5g
--------------------------------------------------------------------------------

Sodium sulfite max solubility at 20C is about 260g/L this is 250g/L. I realize potassium sulfite is WAY more soluble but I don't have any and it's more expensive by a lot. Any idea how to figure out if this will work? Even if it does, I think you end up with about 2/3 what I had in 2B-1 and 2B-4 (which was fine). I may need to make 1/3-1/2 of it metabisulfite in order to keep pH down, but that seems to be about 450g/L max solubility so that should be OK. But I just don't know about the developing agents.

I can mix up a small 30ml sample to test solubility. But if there is a more definitive source, Ill try that!

Raghu Kuvempunagar · May 15, 2021

Second bath should ideally be a single use alkali solution with just one ingredient like Sodium Hydroxide (as in the case of Meritol Fine Grain 2-bath developer) or Sodium Carbonate (as in the case of divided Pyrocat). Would some low concentration sulphite rich variant of 2B-4 with Sodium Hydroxide second bath work well? Not sure I've read anywhere about the use of Sodium Hydroxide in the context of PC developers except this.

relistan · May 15, 2021

Raghu Kuvempunagar said:
Second bath should ideally be a single use alkali solution with just one ingredient like Sodium Hydroxide (as in the case of Meritol Fine Grain 2-bath developer) or Sodium Carbonate (as in the case of divided Pyrocat). Would some low concentration sulphite rich variant of 2B-4 with Sodium Hydroxide second bath work well? Not sure I've read anywhere about the use of Sodium Hydroxide in the context of PC developers except this.

This is along the lines of what I was thinking about above as well. If I can put enough sulfite in A, then B can be simple. Both would be one shot in this scenario. The one shot A lets you adjust concentration for film thickness. I've never tried a hydroxide B but since TSP works well (but with sulfite) and they are close in pH I suspect it would. If I can get all that stuff into solution in A, I'll give your idea a shot.

relistan · May 15, 2021

Well, I did some testing of that formula and even though it didn't go well, I'll post an update. Pleas nobody new show up on this thread, read this, and then troll me about not being successful while in the middle of experimenting.

Here's what I did

I mixed up 33ml of the stock solution. Result: All the ingredients dissolve! This is a good start
I used a 3:1 ratio of sodium sulfite to sodium metabisulfite.
pH of the stock is 6.6, so just at the threshold for phenidone to become active
There is still a small amount of development in A
I mixed up a bath B from NaOH as discussed with @Raghu Kuvempunagar
pH of bath B was 12.8, using 0.8g NaOH to 300ml
I tested B with 20ml of carryover. It develops film like that. But very slowly. You would not get enough density to really see an image.
While attempting to do normal development, I was not seeing a lot of density building on test strips, but given how much of an impact carryover apparently has, I tried with a short section of Ilford FP4+ because it's a "normal" thickness emulsion
FP4+ at EI100
Used 3.5 mins A, 3.5 mins B @ 20C
Result: Very, thin negatives.

It may be that I needed to leave it longer in B. But what I saw from testing snippets of film was not much density change past about 3 minutes (eyeballing fixed results). It may also be that this is just not enough ascorbic acid. It actually has about 50% more phenidone than Relayer's developer. I left out the HEDP/Etidronic acid in this test. I don't know how much effect that might have.

Carryover Amount vs Ascorbate Developers

Developer	Ascorbic/Ascorbate	Phenidone
PC-Glycol	0.6g	0.015g
Relayer	0.2g	0.004g
PG-110B	0.3g	0.03g
2B-4	0.24g	0.01g
Current experiment	0.162g	0.006g

cliveh · May 15, 2021

Isn't this a bit like razors with multiple blades giving you a better shave, when one will suffice?

Advice on my Two Bath Developer

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