Advice on my Two Bath Developer

Raghu Kuvempunagar · May 16, 2021

Karl,

In post #160, I shared a table on using Meritol stock solution in divided development. Out of curiosity, I tested this Meritol-Caustic 2-bath developer on Arista 100 35mm film. Note that the Meritol developer formula is not optimized for modern films which supposedly absorb significantly less amount of developer than films of the past.

Here's what I observed:

If the developer stock is diluted as recommended by the table I shared in a previous post, there's no development in the first bath but the negatives after the second bath are very thin. There is no development due to carryover.

If the stock solution is itself used undiluted in the first bath, the negatives turn out to be relatively better but still thin. There's some development in the first bath but three minutes (recommended first bath time) is a little short. If the first bath is extended to five or more minutes, better negatives might be obtainable. There is no development due to carryover, at least in three minutes.

Nothing surprising here and as warned previously by several more knowledgeable forum members, formulas of yore won't work well on contemporary films without further optimization. But the results add weight to what Ryuji opined - that significant development in the first bath is essential.

relistan · May 16, 2021

Raghu Kuvempunagar said:
Nothing surprising here and as warned previously by several more knowledgeable forum members, formulas of yore won't work well on contemporary films without further optimization. But the results add weight to what Ryuji opined - that significant development in the first bath is essential.

Thanks, very good to have a comparison point as well. Without a heavy concentration of developing agents (which makes a carryover mess—and is thus not a solution), I agree that you must have development in the first bath. This was my experience as I originally posted and it’s nice to have it confirmed by Ryuji and also by your experiment. This was how I designed 2B-1 and it works the best of all of them that I have made (still works 3+ mos later). I may try to raise the pH of A to 8 and see if that does it. I am pretty sure it will.

I have not tried Relayer’s bath A to see what the pH is.

grain elevator · May 16, 2021

Just a quick thought, to prevent the bath B from becoming a developer through carry-over, couldn't the Fenton reaction be your friend and kill off the ascorbate? At least if you do a one-shot bat A anyway, you can leave the sequestering agent out, and if you want to reuse it, maybe there's a threshold where it preserves bath A fine but allows ascorbate carry-over in bath B to degrade?

relistan · May 16, 2021

grain elevator said:
Just a quick thought, to prevent the bath B from becoming a developer through carry-over, couldn't the Fenton reaction be your friend and kill off the ascorbate? At least if you do a one-shot bat A anyway, you can leave the sequestering agent out, and if you want to reuse it, maybe there's a threshold where it preserves bath A fine but allows ascorbate carry-over in bath B to degrade?

It seems possible. I was thinking along the same lines earlier when suggesting that I aeriate B as much as possible. But you'd still end up with phenidone in there, and from my testing it seems to be the one that really causes the carryover development. I've concluded with @Raghu Kuvempunagar and Jay DeFehr and some others, that a simple, throw away bath B is the best option. And I now have some results to show for it! I will post in a minute.

relistan · May 16, 2021

I made up another batch of the formula above from scratch, but adjusted the pH of bath A to 8.2 using sodium hydroxide. I decided to try it out with a straight borax bath B now that I have learned enough about this particular formula. I did some clip tests and established some reasonable times for darkening a leader to an acceptable density (no densitometer, so using a lightbulb that I know how much I should be able to see through a properly developed leader). Times were 4 minutes A, 4 minutes B for a leader of Ilford Delta 100.

I tested it a few frames of Delta 100 like I had done with 2B-4 so that I would have a straight comparison. Very good results! I am pleased with this.

Much finer grain from the lower pH. Actually has less sulfite, but from what @Alan Johnson posted, I was probably just on the threshold of solvency with previous attempts.
Tonality and gradation are just as good at 1:27 P/C ratio as at 1:24, and I still think better than 1:40.
Not quite as sharp as 2B-4 or 2B-1 but better tonality and finer grain—as expected, since sharpness/grain are known tradeoffs
Because of the development in A, I think bicarbonate would be possible for B (with different times in A, obviously), possibly providing even finer grain
I did not need any potassium bromide, at least for Delta 100. Fog is basically nonexistent.

Thinking hard about this developer strategy, I am pretty convinced this is the right way to go. Thanks a ton to @Raghu Kuvempunagar for persistently helping out on this. The strategy we've worked out here seems to be quite good. Appreciate all the help from @Alan Johnson and @michael_r as well!

Summarizing the strategy here:

Do some development in bath A (like 2B-1, also following Ryuji's advice)
All the sulfite is in A
Use a concentrate for bath A so that you make up a batch 1:9 of A each time. This prevents the down side of development in A where byproducts build up.
Because development happens in A you can control for emulsion thickness with different times. You could also control with concentration if desired—though you get more sulfite, too.
Bath B is a simple alkali bath, and borax is totally adequate for this because we can develop in A

Here are some frames from Delta 100 as mentioned above

Here are a couple of these test frames:

I will post the full formula once I've managed to mix up the full concentrate and can post the exact amounts.

relistan · May 16, 2021

Success, but, well, mixing that concentrate was a pain. Getting all that sulfite into solution required stirring and stirring and I substituted the last nearly half for metabisulfite in the end to get it all dissolved. But then had to use quite a lot of sodium hydroxide to bring the pH up to 8.2. The only real difference vs the test I made earlier was that there was no propylene glycol here since I didn't need it to measure the phenidone. Sulfite is not very soluble in it, but maybe it helped the ascorbic acid and phenidone dissolve, making it easier for the sulfite. So I don't have a full formula (don't know amount of NaOH) and will have to post when I mix it up next time. I may try to get some potassium sulfite instead, just to make life easier. That feels like it's probably the right solution. In the end I had to filter it, but what I filtered was extremely fine. If anyone has any tips here, please let me know. Maybe hotter water?

Anyway, here is 2B-6, a concentrate-based phenidone/ascorbic acid two bath. Sample photos in previous post.

Bath A Concentrate — pH 8.2 — Use 1:9

Water — 300ml @ 40C
Phenidone — 1g
Ascorbic Acid — 27g
Sodium Sulfite — 60g
Sodium Metabisulfite — 20g
Etidronic Acid/HEDP — 2ml
Water to 330ml
Sodium Hydroxide to pH 8.2 (I estimate that it's a few grams of this)

Bath B Concentrate — pH 9.2 — Use 1:1

Water — 1L @ 40C
Borax 16.5g

The concentrate for bath A is to be mixed 1:9 so 1 part concentrate to 9 parts water at your preferred temperature. Bath B can be used at least 1:1. Further testing may show that it can be diluted more than this.

Alan Johnson · May 16, 2021

An unconventional approach to use a concentrate.
Emofin just had a fixed part A.
Why is it thought that the small amount of development in part A would be significant?
I mean in relation to changes in the composition of the part A solution.
It just leads to a very low concentration of sulfite in the 1+9 and consequent grain.

Raghu Kuvempunagar · May 17, 2021

Potassium Sulphite is expensive, at least in my country. However, we can use Potassium Metabisulphite and Sodium Hydroxide to make a solution of Potassium Sulphite. Detauils are here:

https://www.facebook.com/notes/the-...olution-of-potassium-sulfite/333964277825173/

relistan · May 18, 2021

michael_r said:
One tip would be to mix the sulfite before the Phenidone, since Phenidone and derivatives are quite a bit easier to dissolve in an alkaline solution (with XTOL, this trick is what allows for room temp mixing - part A of the package is Dimezone-S, sulfite, and the borate alkali/buffer, and then part B lowers the pH to target after the Dimezone-S is in solution).

Thanks Michael, good idea.

Alan Johnson said:
An unconventional approach to use a concentrate.
Emofin just had a fixed part A.
Why is it thought that the small amount of development in part A would be significant?
I mean in relation to changes in the composition of the part A solution.
It just leads to a very low concentration of sulfite in the 1+9 and consequent grain.

Alan, yeah, and I question if this amount of sulfite is actually doing anything. However, I am seeing quite decent grain from these first frames. Admittedly this is Delta 100, which has outstandingly fine grain. I need to stick them on the enlarger to really see the grain difference. With my Epson scanner the grain looks only a little bit more pronounced than Delta 100 negatives from XTOL stock. Gainer suggested that his ascorbic acid developers without sulfite were reasonably fine grain. I didn't find that with PC-Glycol (which I used a lot), but that was with sodium carbonate. Given that, with less sulfite, 2B-6 has finer grain in my test shots than 2B-4, I think pH might be a bigger factor here. But I need to test with something grainier, like Fomapan 400.

The thinking about the concentrate was originally when aiming for an acidic bath A because it would allow you to control concentration for different films. Moving to an alkaline bath A makes that less important. However, you do get the advantage that all of your development should be repeatable because it's fresh developer each time you use it. Not as economical, and definitely limited by sulfite solubility. I will try it out on a few rolls and see how I like working with it.

Raghu Kuvempunagar said:
Potassium Sulphite is expensive, at least in my country. However, we can use Potassium Metabisulphite and Sodium Hydroxide to make a solution of Potassium Sulphite. Detauils are here:

https://www.facebook.com/notes/the-...olution-of-potassium-sulfite/333964277825173/

You are right, I looked and it's very expensive here, also, and really only available as a solution. Sodium metabisulfite is twice as soluble as sulfite, though, and unless I'm misunderstanding, also brings two sulfite ions in the same weight. It can be neutralized with NaOH like your link above, so maybe that's the cheapest and easiest for me to do since I already have NaOH.

Good news on a different note: I ordered an X-Rite 331 densitometer and an X-Rite 396 sensitometer for a very good price, so if they work properly, I ought to be able to do some useful sensitometry (which I need to really read up on). This will hopefully mean I can have some better objective measurements on all of these things.

YoIaMoNwater · May 18, 2021

relistan said:
Thanks Michael, good idea.

Alan, yeah, and I question if this amount of sulfite is actually doing anything. However, I am seeing quite decent grain from these first frames. Admittedly this is Delta 100, which has outstandingly fine grain. I need to stick them on the enlarger to really see the grain difference. With my Epson scanner the grain looks only a little bit more pronounced than Delta 100 negatives from XTOL stock. Gainer suggested that his ascorbic acid developers without sulfite were reasonably fine grain. I didn't find that with PC-Glycol (which I used a lot), but that was with sodium carbonate. Given that, with less sulfite, 2B-6 has finer grain in my test shots than 2B-4, I think pH might be a bigger factor here. But I need to test with something grainier, like Fomapan 400.

The thinking about the concentrate was originally when aiming for an acidic bath A because it would allow you to control concentration for different films. Moving to an alkaline bath A makes that less important. However, you do get the advantage that all of your development should be repeatable because it's fresh developer each time you use it. Not as economical, and definitely limited by sulfite solubility. I will try it out on a few rolls and see how I like working with it.

You are right, I looked and it's very expensive here, also, and really only available as a solution. Sodium metabisulfite is twice as soluble as sulfite, though, and unless I'm misunderstanding, also brings two sulfite ions in the same weight. It can be neutralized with NaOH like your link above, so maybe that's the cheapest and easiest for me to do since I already have NaOH.

Good news on a different note: I ordered an X-Rite 331 densitometer and an X-Rite 396 sensitometer for a very good price, so if they work properly, I ought to be able to do some useful sensitometry (which I need to really read up on). This will hopefully mean I can have some better objective measurements on all of these things.

Wait for real?! Can I send you some of my B&W reversal then? (since Ian something doesn’t live in the UK). Apologies for getting off topic.

relistan · May 18, 2021

YoIaMoNwater said:
Wait for real?! Can I send you some of my B&W reversal then? (since Ian something doesn’t live in the UK). Apologies for getting off topic.

Hey, no worries. Yeah I don't know what I'm doing with them yet but once I've got them and they are working, and I've got a clue, mail stuff over. I'll message you

gorbas · May 20, 2021

Hi Karl, I read with interest your report about being able to develop film in only used bath B.
Well, I can confirm it from my own test.
I used modified Thornton's Bath B (35g of sulphite and 15 grams of Kodalk) after around 8 rolls of film and after 10 minute in B it produced decently developed film. Not fully developed but with very nice density for fully exposed blank film. Interesting!
So, using just once dirt cheap Borax as main alkali make total sense, only issue it is not strong enough.

Raghu Kuvempunagar · May 20, 2021

gorbas said:
Hi Karl, I read with interest your report about being able to develop film in only used bath B.
Well, I can confirm it from my own test.
I used modified Thornton's Bath B (35g of sulphite and 15 grams of Kodalk) after around 8 rolls of film and after 10 minute in B it produced decently developed film. Not fully developed but with very nice density for fully exposed blank film. Interesting!

One wonders if this is a bug or a feature of Thornton's 2-bath developer! As substantial development happens in the first bath of Thornton's, bromide accumulation is inevitable in Part A. This demands increase in development time as more rolls are passed through Part A. But development time in the first bath is fixed through out the life time of Part A. Maybe the additional development that happens in Part B due to the accumulated carry over comes to rescue.

gorbas · May 20, 2021

Hi Raghu, tomorrow I will process clips of film just in A, just in B and A&B. I'm very curious. And I'm just transfering reels from tank with A to tank with B, so carry over is really minimal in this case.

Raghu Kuvempunagar · May 21, 2021

gorbas said:
Hi Raghu, tomorrow I will process clips of film just in A, just in B and A&B. I'm very curious. And I'm just transfering reels from tank with A to tank with B, so carry over is really minimal in this case.

Goran, that sounds like an interesting experiment! Coming to carry over, even if it is little, there's accumulation in Part B when many rolls are developed. Further, I suspect some of the developer absorbed by the film diffuses out into Part B in the second bath. I did some tests, with a different developer, in day light ensuring minimal carry over and still could see Part B developing on its own.

relistan · May 21, 2021

gorbas said:
Hi Karl, I read with interest your report about being able to develop film in only used bath B.
Well, I can confirm it from my own test.
I used modified Thornton's Bath B (35g of sulphite and 15 grams of Kodalk) after around 8 rolls of film and after 10 minute in B it produced decently developed film. Not fully developed but with very nice density for fully exposed blank film. Interesting!

Hi Goran, this is very interesting. I had not tried this with Barry Thornton's two bath when I used it a lot. It does make sense that even with an MQ developer build-up would eventually be a problem. I wonder how many films it takes before that starts to happen?

gorbas said:
So, using just once dirt cheap Borax as main alkali make total sense, only issue it is not strong enough.

Yes, this was my experience with Barry Thornton's Two Bath also. You have to use a pretty strong alkali, because, even though some development happens in A, it's not very much and you would have to leave it in A for quite a long time to get away with Borax as a bath B. I think you would also end up with a pretty flat looking negative (this is what I recall from testing 10 years ago). The nice thing about these phenidone/ascorbate developers is that they are quite active and the borax seems to be totally fine if you have enough developer present!

Raghu Kuvempunagar said:
One wonders if this is a bug or a feature of Thornton's 2-bath developer! As substantial development happens in the first bath of Thornton's, bromide accumulation is inevitable in Part A. This demands increase in development time as more rolls are passed through Part A. But development time in the first bath is fixed through out the life time of Part A. Maybe the additional development that happens in Part B due to the accumulated carry over comes to rescue.

Interesting idea. I am pretty suspicious that the amounts don't line up properly. I used that developer a bunch but never got consistent results from it, which was one of the reasons I stopped using it. I wonder if this was one of the reasons...

Raghu Kuvempunagar said:
Goran, that sounds like an interesting experiment! Coming to carry over, even if it is little, there's accumulation in Part B when many rolls are developed. Further, I suspect some of the developer absorbed by the film diffuses out into Part B in the second bath. I did some tests, with a different developer, in day light ensuring minimal carry over and still could see Part B developing on its own.

I thought when we were talking about "carryover" we were talking about liquid on the film—and liquid absorbed into the film. My assumption (wrongly?) of the 20ml number was that this was largely what was absorbed into the film. My belief is that this is a larger amount than what is carried over on surfaces.

Raghu Kuvempunagar · May 21, 2021

relistan said:
I thought when we were talking about "carryover" we were talking about liquid on the film—and liquid absorbed into the film. My assumption (wrongly?) of the 20ml number was that this was largely what was absorbed into the film. My belief is that this is a larger amount than what is carried over on surfaces.

Carryover is all liquid that gets transferred from one bath to another. It includes the liquid on the surface of the film as well as on the reel, central column, inner walls and the lid. Carryover also includes the liquid that diffuses out of the film in the second bath.

A few drops of Photoflo in the first bath can reduce the carryover but it doesn't fully eliminate it. Inversion agitation invariably deposits some droplets of Part A on the lid of Patterson tank during the first bath which get mixed with Part B in the second bath. If you're transferring the reel from one tank to another as Goran does, then you can reduce the carryover. But nothing can stop developer absorbed by the film diffusing into Part B in the second bath. Ideally development in the second bath should be very fast and exhaust all the developer absorbed by the film before substantial diffusion happens.

gorbas · May 21, 2021

Hi Karl and Raghu, Thank you for your comments! Today I did develop my test. Thornton was used previously for about 10 rolls of 35mm. I did filter out both A and B before this run. I can see dirt accumulation on negatives and I'm not used to it. That is reason why I did use one shot developers for the last 30 years. But I can see some nice benefits of this two bath developer, especially with Ilford Pan F. Both film clips developed in just A or just B can be printed on harder grade of paper. A+B for 5 min each looks normal to me, just as I like. Of course, I can run them for shorter in both baths, but I still don't see reason why I should do that?
Looking forward to see your results Karl with Vitamin C and Phenidone in A bath.

Raghu Kuvempunagar · May 21, 2021

Hi Goran, a picture is worth more than thousand words indeed! Thanks so much for showing that substantial development happens in both baths of T2B. The second pic is particularly interesting as it shows that carryover accumulation is indeed an important factor in T2B.

gorbas · May 21, 2021

You are welcome Raghu! I forgot to mention that this picture of all 3 negatives is one shot and with same adjustments. Just A bath clip is least developed, just B is a touch more. Clip with A+B is "normal".

Raghu Kuvempunagar · May 22, 2021

gorbas said:
Just A bath clip is least developed, just B is a touch more. Clip with A+B is "normal".

It's noteworthy that Part B by itself does as much or slightly more development than Part A after 10 rolls have passed through it. Demolishes the myth that BT2B is carryover proof.

Alan Johnson · May 22, 2021

The Barry Thornton 2-bath does not give rise to this problem if it is not used very often and the part B kept in a part full container. Then the metol carried over to part B gets oxidized between processing of films and becomes inert.

In my tests I found the BTTB developer to give only a small amount of development in carry over. It was the phenidone ascorbate developers that that gave rise to significant development in the carry over, and why I questioned Relayer on his developer.
https://www.photrio.com/forum/threads/diafine-revisited-ascorbate-version.78123/

Raghu Kuvempunagar · May 22, 2021

Alan Johnson said:
The Barry Thornton 2-bath does not give rise to this problem if it is not used very often and the part B kept in a part full container. Then the metol carried over to part B gets oxidized between processing of films and becomes inert.

A simpler solution is perhaps to prepare and use 2 liters of Part B instead of the recommended 1 lier. This is a little wasteful, but the concentration of accumulated carryover is halved due to the doubling of volume of Part B and consequently it will be much weaker as a developer. Discard Part B after 15 rolls as recommended by Thornton.

And it might also be useful to use Patterson style tanks that take double the volume of Part B than steel tanks for developing the roll. Again, the idea is to reduce the concentration of carryover in Part B in the second bath.

gorbas · May 22, 2021

Raghu, I was little naive regarding separate development in bath A and carry on "contamination" in part B. I expected it to be ideal, but it's not and I'm glad I did the test. But I can not see any negative effect of it on developing film. It does not harm film in any way. Do I miss anything?
Mixing A and B in batches of 2 or 3 liters will be ideal for me, if T2B is my main developer. That way I can use it with 5 reels tank. What also surprised me is how "muddy" bath A was after 8 rolls? It left nice layer of fine gray deposits on filter paper. It was also hard to clean walls of glass bottle from deposits from Bath B. Maybe I need better brush?
So far I used T2B with Kentmere 100, Ilford Pan F, Fuji Acros and Kodak Verichrome (expired in 1969) and Plus X and I'm happy with results.

gorbas · May 22, 2021

I just adjusted white and black levels on those DSLR scans

Advice on my Two Bath Developer

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