Two bath developers

I estimated an approximate formula for Emofin,see post 172:
www.apug.org/forums/forum37/59223-microdol-x-replacement-18.html
Part B has an unusually high pH, ~12.That may be the reason for the speed increase.
Bill Troop notes the " balance of conventional probabilities" how Emofin may work,post 182.

Donmck said:

I think the misconception is ---with the old films and formulas,you are loading up the emulsion in the 'A" bath and then doing the development in the "B" bath.
With modern film,you are developing the film "to a point" in the "A" bath so that the small carryover of developer in the thinner emulsion is sufficient to finish the development in the shadows while exhausting in the highs.I agree with olehjalmar ---- " so it is reasonable that the time in A will influence the contrast."

-Don

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Regardless of whether you are working with an old film or a new film whether you get any development in Solution A depends on the developer formula, not the film. With a developer like divided D23 it is possible to get quite a lot of development while the film is in Solution A. With divided Pyrocat-HD, on the other hand, you will get almost no development in Solution A.

Sandy King

"Regardless of whether you are working with an old film or a new film whether you get any development in Solution A depends on the developer formula, not the film."

I was speaking in generalities---and I believe what you are suggesting is the exception and not the rule.I think most would look at the "old school" 2 bath
developers as the Stoeckler variants ----metol/ss "A" bath. So, yes I should have said--"generally speaking.

-Don

I think the question of old films vs new ones in older developers vs new ones complicates this discussion. When we talk on new thin films in the new developers and acknowledging they might not work as well in some of the older ones. This was the reason that Barry Thornton tweaked his developer for new thinner films.

As ever, the range and diversity of backgrounds (and interests) at APUG makes it dangerous to generalize.
(let me tattoo that to my forehead)

Our sources of data, however, is always a constant problem. Much of what we encounter have been iterated for generations,
poisoning the well, so to speak. For instance, the complaints that 'new thin films' don't work with 2 bath developers go back to the early 1950s, usually mashing up the observations that Ansel Adams made describing his experience with pre WW2 films and post WW2 !

For an american photographer of a certain age, D-23 and Diafine are the 2 baths that we think about.

A little older, and the Leitz 2 bath comes to mind. A little younger, and the Farber-Vestal D-76 formula is in our mind. All, long before Thornton.

Primary sources are essential to good scholarship, but even more important in photography is the understanding that what is written down, despite its provenance, might not have any usefulness for my own work, and the only way to know is to try it out.

Above all, don't try to extrapolate or project another's success or failure beyond the scope of their work. I only wish I could sit down with Thornton and ask him about stuff. I only wish.

Finally, I'm just plain jealous I didn't come up with any of the Pyrocat series....don't tell Sandy.

df cardwell said:

As ever, the range and diversity of backgrounds (and interests) at APUG makes it dangerous to generalize.
(let me tattoo that to my forehead)

Our sources of data, however, is always a constant problem. Much of what we encounter have been iterated for generations,
poisoning the well, so to speak. For instance, the complaints that 'new thin films' don't work with 2 bath developers go back to the early 1950s, usually mashing up the observations that Ansel Adams made describing his experience with pre WW2 films and post WW2 !

For an american photographer of a certain age, D-23 and Diafine are the 2 baths that we think about.

A little older, and the Leitz 2 bath comes to mind. A little younger, and the Farber-Vestal D-76 formula is in our mind. All, long before Thornton.

Primary sources are essential to good scholarship, but even more important in photography is the understanding that what is written down, despite its provenance, might not have any usefulness for my own work, and the only way to know is to try it out.

Above all, don't try to extrapolate or project another's success or failure beyond the scope of their work. I only wish I could sit down with Thornton and ask him about stuff. I only wish.

Finally, I'm just plain jealous I didn't come up with any of the Pyrocat series....don't tell Sandy.

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Well said! I am interested in the application of todays two baths with todays film - how we increase speed if required and also if they are combinations that work particularly well together. A general positive consensus would indicate a point from which to start to experiment on how I need to tweak for my particular - peculiar - way of working.

In the last two weeks I had to buy Ilford Delta 400 as opposed to HP5+ which I have used exclusively along with FP4+. I followed Sandys advice and appear to have really nice negs. Is it this two bath or is it the film or the combination. What I have just done is order another 20 rolls of 120 Delta 400 and will let you know more of my experiences as we go.

df cardwell said:

Primary sources are essential to good scholarship, but even more important in photography is the understanding that what is written down, despite its provenance, might not have any usefulness for my own work, and the only way to know is to try it out.

Above all, don't try to extrapolate or project another's success or failure beyond the scope of their work. I only wish I could sit down with Thornton and ask him about stuff. I only wish.

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That is a good point. There is almost always a good reason for what is in the literature, but on closer examination it might not apply to our own work. That is why I usually test things for myself.

A case in point is the literature about two-bath development. Last year (believe it was last year, but time goes so fast) I published an article in View Camera magazine on two-bath development. In response to this article I received a lot of personal emails from people who assured me that certain thins I said were not correct. I will put the general wisdom in three categories.

1. Some of your testing was done with constant agitation. Don't you know this does not work with two-bath development.

2. You recommended a pre-soak. You should know this is not good practice for two-bath development.

3. Some of your testing was done with modern T-grain emulsion films. The literature is clear that modern films do not work with two-bath development.

My response to all three comments was the same. I tested the procedures and they worked for me with the film and conditions described. That is probably not the whole truth, but it is my truth and I am sticking to it.

A final comment about the pre-soak. I don't believe the pre-soak is necessary for most films, but for some thin emulsion slow speed films it seems to help a lot in giving even development. What I speculate is that these emulsions are very hard and need some time to soak so that the gelatin can expand and absorb the reducer in Solution A. Without the pre-soak the emulsion will absorb very little of Solution A, which would give very weak negatives regardless of how long you develop in Solution B. However, in lieu of the water pre-soak one might just double the time in Solution A. I speculate that this would result in the same end.

Regardless, what is certain is that there is quite a bit of fine-tuning that can be done with two -bath developers to increase contrast, increase effective film speed, or change the curve. If you know the principles of this type of development it is easy to apply these personal controls to get better negatives for your own work.

Sandy King

I must try and get hold of a copy of your article Sandy!

Just wish I could get more Cachet AB 55. I liked it for my Plus-X and Ilford Pan F+.

What I speculate is that these emulsions are very hard and need some time to soak so that the gelatin can expand and absorb the reducer in Solution A.

Sandy,

After decades of using Agfa 400 @ Rodinal 1+50 for 11 minutes,
a case of the 'new, improved version' showed up at my studio
and it wanted 30' in Rodinal... D-76 times had increased from 11 minutes to 14 minutes.

The speculation from Agfa USA was that aliens had overtaken the factory and were trying to kill them all.

What they might have done to the new film to create such a wild new time,
I never found out. But I'll toss this out, and give your speculation a loud AMEN.

Oh, and I sent the film right back.

Alan Johnson said:

I estimated an approximate formula for Emofin,see post 172:
www.apug.org/forums/forum37/59223-microdol-x-replacement-18.html
Part B has an unusually high pH, ~12.That may be the reason for the speed increase.
Bill Troop notes the " balance of conventional probabilities" how Emofin may work,post 182.

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Alan,thanks for posting that.I understand now why some people were a little put off when they tried it.It almost looks a little like Super 20 on steroids(disclaimer to follow.)As I said,I don't think I would have much use for it as I don't shoot in that kind of low light very often.I wonder if diafine is the same type of developer?

-Don

[Disclaimer-I'm a street shooter using vintage/antique cameras .I don't use the zone system and rarely even use a meter.I mostly shoot 35mm but also shoot some 6x9 and 5x7 .All my comments should be taken in that context.Also,I'm not a chemist,nor a scientist.I don't do any scientific testing.All of my comments are off the cuff and are not sworn to on a stack of Bibles,nor written in stone---they are...Opinion.(I'm sure I'll have to add to this at some point =))
Finally,to quote Sir Charles Popper-

"It is impossible to speak in such a way that you cannot be misunderstood"

www.digitaltruth.com/products/acufine.php
The major constituents of Diafine are sulfite,hydroquinone,probably phenidone or dimezone,with carbonate in the part B. Emofin has sulfite,metol,with carbonate plus the grain solvent p-phenylenediamine in part B.They probably work in the same way in that the developer exhausts in the highlights in part B and the shadows continue to develop.
It's interesting that both these speed increasing developers use the high pH carbonate part B.In some way it appears that the high pH makes the shadows develop more.

grain solvent p-phenylenediamine

major constituents of Diafine


PPD is not a grain solvent, it is a pH neutral, very weak developer that has the effect of activating some other developer (like glycin) which normally only functions at high pH. By allowing glycin, for instance, to function at a very low pH as it would in a strong carbonate solution, you get a mechanism that gives fine grain, full speed, excellent tonality, and good sharpness. (Edmund Lowe, Edwal patent information; my own long experience with Lowe developers).

I would expect PPD to be in part A. It seems to slightly increase metol's activity, and if Emofin has much sulfite in A, it would be developing the image. I've never used Emofin, but I'd expect metol to be fully active, like D-23 - if not more so ! Interesting to find out.

Diafine has all this stuff in each and every can:Sodium Sulfite, HQ, TSP, Citric Acid, Potassium Bromide, Phenidone, Sodium BiSulfite, Sodium Carbonate. (according to a 1987 MSDS)

DF,thanks for the correction, the PPD is indeed in part A.
However, the Film Developing Cookbook p 68 notes that when PPD is is combined with a more active developing agent,that agent is mainly responsible for density and PPD is relegated to a minor role as a subsidiary solvent.FDC p65 notes the ancient way of making super-fine grain developers was to use a a developing agent that has a high solvent effect such as PPD.
Crawley BJP Dec23 1960 described"..the solvent-reducer paraphenylenediamine."

IMO it is more interesting that high pH increases film speed,more silver is actually produced, I never saw a chemical explanation for that.

df cardwell said:

major constituents of Diafine

Diafine has all this stuff in each and every can:Sodium Sulfite, HQ, TSP, Citric Acid, Potassium Bromide, Phenidone, Sodium BiSulfite, Sodium Carbonate. (according to a 1987 MSDS)

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Wonder why both sodium carbonate and TSP?

Sandy King

They work together as a buffer, I've just read something specifically about this combination from the 1920's or 30's on super fine grain developers. Don't ask which of about 15-20 books While I left most of books are in the UK I've scanned the relevant pages & PDF'd them, it may have been Windisch - I only spotted it yesterday so it shouldn't be to hard to find.

Ian

Diafine (1986 msds)
(A) www.hazard.com/msds/f2/bdz/bdzmq.html
(B) www.hazard.com/msds/f2/bdz/bdzmr.html

Otto: Apes don't read photochemistry.
Wanda: Yes they do, Otto. They just don't understand it

Call me Otto.

Christmas, 1998.

Breathlessly reading Troop's description of developers, and smacking into the PPD = silver solvent bit, I was confused again. I got the Crawley extract about "PPD+ replenishment + minimal agitation = magic", yeah, I KNEW that, but silver solvent ? I thought, isn't that what makes Microdol mooshy, and fogs film like that DK20 stuff ?

But wait, that's what Schwalberg told me Sulfite was, and that Rodinal was magic, and that's what Troop just said.

And one thing for sure, in 1998 I had 31 years of excellent negs from Edwal 12, with no fog, and no moosh.

So. I KNOW PPD isn't a grain dissolver, because it doesn't dissolve grain.

I don't know if ANYTHING really dissolves grain. Now, thiocyanates were widely used in the late '30s to make 'fine grain, and they were likely to either give fine grain by restraining action, at a severe speed loss, or fog, if there was too much restrainer used.

To me, there were two important fine grain developers, DK-20 and Edwal 12. DK-20 was a moderate pH developer with thiocyanate, and it made grain like D-76. Edwal 12 used no restrainers, and made very fine grain indeed. And no fog.

With a couple exceptions, all the rest of the fine grain developers were witches' brews, and best left in obscurity. They used PPD, and everything else in the shed to make a magic brew, which didn't really work.

So, when Crawley or Troop write about PPD and solvent developers, which developers are they talking about.

With the text in my left hand and the negative in the enlarger, I know there is a context problem. Troop and Crawley are probably correct, but they are clearly not describing the developer I'm using. If PPD is not a GRAIN solvent, because my negatives are both sharper and finer grained than similar developers with no PPD.

If there is a difference between Grain solvent, and SILVER solvent, and a solver solvent can still make a sharp developer, then that agrees with my evidence. In any case, I hope somebody understands this, I don't. Except the part about E-12 being a totally brilliant developer.

IAN ?

.

df cardwell said:

Otto: Apes don't read photochemistry.
Wanda: Yes they do, Otto. They just don't understand it

IAN ?

.

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Otto

When people talk about PPD Solvent developers they generally mean the Sease/Dupont formulae, the series of 4 and then other similar PPD devloper combinations, and the solvent effect is due to the high levell of Sodium Sulphite.

There's a small amount of physical development taking place in solvent developers this was increased in developesr like DK-20.

In many ways the approach used in Edwal 12 is close to the earlier Johnsons Meritol based formulae, Meritol being the combination product of PPD and Pyrocatechin, Meritol was the basis for a number of Very Fine Grain developers marketed in the UK and it's colonies before and adter WWII, all have high Sulphite content.

Ian

"IMO it is more interesting that high pH increases film speed,more silver is actually produced, I never saw a chemical explanation for that"-Alan Johnson


I don't doubt that's interesting to the chemists-----but for me, the main event here is the tonality(contrast?).
Somehow between the replenished developer,the full emulsion speed the "automatic contrast control" and the sod.carb. second bath----I get MF tonality on 35mm film.

Keeping my 1L batch of replenished developer balanced between fully ripened and no bromide drag took a little practice, but it's been well worth the trouble for me.

-Don

sanking said:

Before committing *some* rolls to an unknown procedure I would suggest you commit one test roll using a 1:15 dilution for both Solution A and B, 5 minute pre-soak at 75F, 5 minutes in Solution A at 75F and 5 minutes in Solution B at 75 minutes. Make sure you agitate vigorously at the beginning of development and ten seconds every minute during development.

Evaluate your results and make adjustments as necessary. Negatives too strong, change dilution to 1:20, to weak change to 1:10.

Sandy King

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Hi everybody,

I need some advce.

I just received my Pyrocat HD and plan to use it on the followng film:

1) Ilford HP5+ ; and
2) Lucky SHD 100

Both are 35mm films.

Am I correct to say that if I'm using a two bath developer, the film speed and type of film does not matter. In alll cases, I simply follow Sandy's suggested 1:15 concerntration, at the recommended times?

In addition, I've read on the "largeformatphotography thread" that Sandy suggests using "photoflo" (see below).

Am I correct to say that photoflo is a generic term and Ilford's "Ilfotol" qualifies?

In addition, I'm using Ilford Rapid Fix (which I've read from Sandy's article, is ok and
Ilford "Ilfostop" stop bath. Does Ilfostop qualify as an "acetic" stop bath? It's description sounds like it does but I've no clue...


Any assistance given will be appreciated. Thanks


Sandy's directions in the large photography forum are set out below

a. Use a 1:15 or 1:20 dilution of Pyrocat Stock A and Stock B for most films. Add a few grams of PhotoFlo to the solution.
b. Pre-soak the film for two or three minutes in water at 75º F.
c. Develop for five minutes in working Solution A, at 75º F. Then drain the film for 15 seconds.
d. Develop for five minutes in working Solution B, at 75º F.
e. Use a 1/2 strength acetic acid stop bath for 10 seconds.
f. Fix in any standard fixer. I use an alkaline fixer (TF-3) but the use of a slightly acidic fixer is ok.
f. Wash the film for 10-15 minutes, drain and dry.