Two bath film development queries

dancqu · Jun 21, 2008

I was for a short time infatuated with two bath development.
Now, as I see it, the point of using a two bath is compensation.
So I now reason why not use a single bath compensating developer.

I've had very good results with a formula very similar to D-23.
D-23 is not a 'Classic' developer of the compensating type. When
used at a dilution of 1:7 with some what protracted development
the picture changes. My impression is one of very noticeable
compensation while maintaining full film speed.

Details: 1 liter working strength; 1 gram metol, 10 grams sodium
sulfite -- at 22 centigrade 500ml per roll of 120 -- Agitation after
start, 3 inversions each 2 minutes. Dan

Figital Revolution · Jun 21, 2008

I agree than no agitation WOULD be ideal but it is not really possible due to bromide drag and uneven development in most modern emulsions. In all of the films I have tested (15 and counting) for Figital Revolution and BKA (the dist for Diafine) agitation is better than no agitation for the above mentioned reasons and the advantages of no agitation with Diafine do not out weigh the problems. I feel that Diafine is the perfect develper for BW film for scanning purposes - I will be posting two new articles on Diafine in the coming week on Zone Plate and Pinhole Photography and on High Res Films (Part 2, will include time and tech) using Diafine.

Murray Kelly · Jun 21, 2008

dancqu said:
I was for a short time infatuated with two bath development.
Now, as I see it, the point of using a two bath is compensation.
So I now reason why not use a single bath compensating developer.

I've had very good results with a formula very similar to D-23.
D-23 is not a 'Classic' developer of the compensating type. When
used at a dilution of 1:7 with some what protracted development
the picture changes. My impression is one of very noticeable
compensation while maintaining full film speed.

Details: 1 liter working strength; 1 gram metol, 10 grams sodium
sulfite -- at 22 centigrade 500ml per roll of 120 -- Agitation after
start, 3 inversions each 2 minutes. Dan

I well remember the thread and I apologise for Gainer and myself for stealing it. :-(

Re the Diafine, just for interest I measured the pH of my year old Diafine A & B.
The A was 10.7 which astounded me. I have been most careful never to cross contaminate the two baths. The B bath was a more expected 10.4. One would think that development would certainly occur in 'A' at that pH.

I mixed some more A and it was 7.3 fresh. The Citric acid must 'die' sometime. The homebrew formulae use bisulfite - perhaps for good reason?

Murray

dancqu · Jun 21, 2008

Murray Kelly said:
I mixed some more A and it was 7.3 fresh.
The Citric acid must 'die' sometime. The homebrew
formulae use bisulfite - perhaps for good reason?

Sulfites and bisulfites die; oxidize. Often mentioned
in regard to sulfite HCAs.

At a ph of 10.7 and with the developer at good strength
otherwise development will be quick. Dan

dancqu · Jun 22, 2008

Murray Kelly said:
Re: the Diafine, just for interest I measured the pH of my
year old Diafine A & B. The A was 10.7 which astounded me.
I have been most careful never to cross contaminate the two
baths. The B bath was a more expected 10.4. One would think
that development would certainly occur in 'A' at that pH.

I mixed some more A and it was 7.3 fresh. The Citric acid
must 'die' sometime. The homebrew formulae use bisulfite
- perhaps for good reason? Murray

How a ph of 10.7 could develop in the A bath I've no
idea. More the ph of a carbonated very active developer.
Citric acid may oxidize as do ascorbic and oxalic acids.
Acidifying the A bath works to inactivate. At ph 7.3
and with phenidone the principle agent I'd expect
VERY thin negatives with several minutes
development. Dan

Murray Kelly · Jun 22, 2008

dancqu said:
How a ph of 10.7 could develop in the A bath I've no
idea. More the ph of a carbonated very active developer.
Citric acid may oxidize as do ascorbic and oxalic acids.
Acidifying the A bath works to inactivate. At ph 7.3
and with phenidone the principle agent I'd expect
VERY thin negatives with several minutes
development. Dan

My thoughts exactly. How it got to that pH is a mystery to me.
I used it about a month ago and all was well then. I'm half way thru a roll of 127 in the Yashica-44LM (which is what the last film was exposed in) so when I am ready I will have a chance to try it again.
Murray

Paul Verizzo · Jun 23, 2008

My Diafine Notes

Murray Kelly said:
Re the Diafine, just for interest I measured the pH of my year old Diafine A & B.
The A was 10.7 which astounded me. I have been most careful never to cross contaminate the two baths. The B bath was a more expected 10.4. One would think that development would certainly occur in 'A' at that pH.

I mixed some more A and it was 7.3 fresh. The Citric acid must 'die' sometime. The homebrew formulae use bisulfite - perhaps for good reason?

Murray

From about 1994, I noted that Diafine Bath A weighted 44.5 grams dry and freshly mixed (Denver city water) had a pH of 8.2. "Hydroquinone visible." Bath B weighed 80 grams and had a pH of 10.5. "Visually appears to be sodium sulfite." The pH and the MSDS confirm also sodium carbonate.

pH test was by pHydrion test paper. If you figure maybe 5-10 grams hydroquinone in Bath A, an inconsequential amount of Phenidone, that leaves maybe 35-40 grams of sodium sulfite in Bath A.

Bath B having a pH of 10.5 probably has about 5-10 grams of carbonate, so the balance of of Bath B is 70-75 grams of sulfite.

Interesting that I could recognize the crystal forms, although obviously I knew what they might be.

If citric acid is a component, it didn't show in the Bath A pH. At pH 8.2 there definitely would be some developing going on in that bath, especially with Phenidone.

Murray Kelly · Jun 23, 2008

Paul Verizzo said:
From about 1994, I noted that Diafine Bath A weighted 44.5 grams dry and freshly mixed (Denver city water) had a pH of 8.2. "Hydroquinone visible." Bath B weighed 80 grams and had a pH of 10.5. "Visually appears to be sodium sulfite." The pH and the MSDS confirm also sodium carbonate.

pH test was by pHydrion test paper. If you figure maybe 5-10 grams hydroquinone in Bath A, an inconsequential amount of Phenidone, that leaves maybe 35-40 grams of sodium sulfite in Bath A.

Bath B having a pH of 10.5 probably has about 5-10 grams of carbonate, so the balance of of Bath B is 70-75 grams of sulfite.

Interesting that I could recognize the crystal forms, although obviously I knew what they might be.

If citric acid is a component, it didn't show in the Bath A pH. At pH 8.2 there definitely would be some developing going on in that bath, especially with Phenidone.

Using a US gallon as being 3.8L (it's a lttle under, IIRC) I got similar weights for the powder - 46g/L and 85g/L for A and B.
From the MSDS (dated 1986) I finally ran down, there is sulphite (75-85%), HQ (% not quoted), sodium phosphate tribasic (<5%), citric acid (<5%), KBr (<5%), and phenidone (<5%)

Part B is Na2SO3 60-70%, Na2CO3 20-30%, NaHCO3 <10%, Sod. Phosphate tribasic <5%.

It could easily have morphed since. pH measurements were done with a meter I bought off the e-bay with a claimed accuracy of .1pH from 0-14. I take that with a grain of salt but it's doubtless giving ball-park readings. Hence my confusion when I actually did the deed and take a pH reading.

I managed to 'bludge' some citric acid today and will try to see what if anything hapens if I use some to drop the old batch back to near neutrality. I read somewhere that development in the first bath can be reduced dramatically with the addition of sugar up to 200g/L. That could be one way to get minimal dev. in bath 'A' just as one expects of a two bath process?

I am looking forward to your experiments with the films you talked about, above. v.s.

Thanks
Murray

Murray Kelly · Jun 23, 2008

If you wonder what the heck I'm talking about other films don't be. It should've been directed at Figital!
Sorry.
Murray

Paul Verizzo · Jun 23, 2008

Where did you find such MSDS's?

Murray Kelly said:
Using a US gallon as being 3.8L (it's a lttle under, IIRC) I got similar weights for the powder - 46g/L and 85g/L for A and B.
From the MSDS (dated 1986) I finally ran down, there is sulphite (75-85%), HQ (% not quoted), sodium phosphate tribasic (<5%), citric acid (<5%), KBr (<5%), and phenidone (<5%)

Part B is Na2SO3 60-70%, Na2CO3 20-30%, NaHCO3 <10%, Sod. Phosphate tribasic <5%.

Thanks
Murray

The only ones I have found on the internet are 2002 version; Bath A 10-15% hydroquinone and Bath B only lists 20-30% sodium carbonate.

Maybe the lawyers got smart and realized that they don't have to give all the secret ingredients away. I think, although I can't prove it, that ingredients are sometimes listed either as a decoy or in case they ever decide to incorporate them, they are already on the MSDS.

Something we have to keep in mind is that the MSDS lists the component percentages as part of the dry powder. We are used to thinking in terms of the entire, mixed with water solutions. So, if HQ is 10-15%, that is 4.4 to 6.6 grams, pretty much to be expected.

And, ANY amount of TSP in bath A would cause it to go ballistically alkaline, but then, maybe that's why the citric acid is in it. I can't imagine ANY reason to add a base and then an acid. To what end? The probable amount of sodium sulfate would give that 8.2 pH I noted. Another head scratcher.

Looking at Bath B, your MSDS lists, effectively, 50-60 grams of sulfite, 16-24 grams of carbonate, 8 grams or less of good old baking soda to form a buffered bath with the carbonate, and 4 grams or less of that pesky TSP once again. Cheap alkali???? Raise the pH after the bicarb lowers it from the carbonate? Odd way to go about it.

What it boils down to is a basic PQ developer and a buffered alkali in Bath B. Whew!

gainer · Jun 23, 2008

In the early days of 2-bath, before Diafine, we would use sugar to increase the amount of developer carried over to the second bath by virtue of the added viscosity. Kodak had a rapid processing machine called "Viscomat" which used the 2 bath method in a continuous flow wherein the viscous developer adhering to the film surface was activated by a sprayed-on second bath.

When I made my first densitometer and was able to measure characteristic curves, I discovered that the vaunted advantages of using D-23 as a 2-bath were imaginary. The major advantage was in the prevention of overdevelopment. I did use a fair amount of Diafine when it came out, but mostly for the convenience of less need for time and temperature control. I also relished the convenience of Varigam.

.

Murray Kelly · Jun 23, 2008

Mmm. Does look odd I agree.

Patrick, I only quote from recieved knowledge abt. the sugar. Apparently was used in the 30's for slowing down 1st bath by some Kodak chemists.
Murray

Paul Verizzo · Jun 23, 2008

Interesting, Patrick

gainer said:
In the early days of 2-bath, before Diafine, we would use sugar to increase the amount of developer carried over to the second bath by virtue of the added viscosity. Kodak had a rapid processing machine called "Viscomat" which used the 2 bath method in a continuous flow wherein the viscous developer adhering to the film surface was activated by a sprayed-on second bath.

When I made my first densitometer and was able to measure characteristic curves, I discovered that the vaunted advantages of using D-23 as a 2-bath were imaginary. The major advantage was in the prevention of overdevelopment. I did use a fair amount of Diafine when it came out, but mostly for the convenience of less need for time and temperature control. I also relished the convenience of Varigam.

.

Wouldn't it take a heck of a lot of sugar to increase velocity? There are a lot better thickeners out their, gram for gram.

Paul Verizzo · Jun 23, 2008

Murray Kelly said:
Mmm. Does look odd I agree.

Patrick, I only quote from recieved knowledge abt. the sugar. Apparently was used in the 30's for slowing down 1st bath by some Kodak chemists.
Murray

So how did you come across those old MSDS'?

gainer · Jun 23, 2008

30's are too far back even for me. The Viscomat process was used for processing of movie film. I read about it in a Kodak manual on movie film processing. I was not trying to contradict your statement, though it may have seemed so.

I doubt that Kodak used sugar in the Viscomat process. The first developer was probably something like HC110 syrup without the DEA. A PQ-glycerol solution might be worth a try for the first bath. I think I have some PC in glycol I might try. It needs an activator, which could be just about anything basic. Come to think of it, I think I have some PC in glycerol, which is much more viscous than glycol.

Murray Kelly · Jun 23, 2008

Hi! I don't have msds for 1930's stuff. but see below for the quotes I made re 1986 diafine.

http://hazard.com/msds/gn.cgi?query=INCORPORATED&start=50&whole=partial
http://www.freelists.org/archives/pure-silver/02-2008/msg00221.html

As for the sugar, glycol, glycerol, or even methyl cellulose at a guess, Kodak apparently had used sugar to tame Leica divided developer (SD-4,5 and 6) called divided press developers and Ilford once had one too. I have tried to find it but the reference was to IIRC ID-44 or ID-66 (not sure which, now).

I have used a polycellulose to slow down a stand developer but it came out a bit blotchy and I was left with the impression I'd overdone the cellulose bit or didn't aggitate enough. Never went back to try again. Still have the polycellulose 1%. I remember doing a google on methyl cellulose and it was pretty definite that small %ages really slowed down reactions.

I think sugar would slow down the molecules at 100-200g/L. I have even seen it suggested the same qty. of Na2SO4 as an alternative, to make things sluggish enough to stop 1st bath development 'completely'. Not my words.

Patrick, I am wide open to contradiction, here. This is all fairly 'unusual technique' stuff.

Murray

Murray Kelly · Jun 24, 2008

I checked - the Ilford was ID44 and it had glucose in it. It was in a Focal Press book titled 'Developing - the negative-technique' by C I Jacobson. Mentions Crabtree et al. and others whom I've never heard of but should. It was the 10th edition 1950 (1st in 1940). In are mentioned triethanolamine and a whole lot of stuff I read but quickly forgot.

He recommends a total amount of sugar equal to the total amt. of SO3 + CO3 or NLT 10% of the total weight of chems.

What goes around, comes around.

Murray

gainer · Jun 24, 2008

A miracle happened. I found my copy of EK's "MOTION PICTURE FILMS FOR PROFESSIONAL USE" , 49 pages of information from sometime around 1960. There's no publication date I can find, but the latest reference is to an article publushed in 1960.

All it says about the developer used in the Viscomat process is that it had thickening agents, was applied to the film in a continuous transport machine, and developed the film while in transport to the fixing, washing process and drying pocesses. If they used sugar in this process, it was propably to keep the developing solution on the film. It was not a 2-bath process in the sense we use the term. That's not to say they didn't use it in some process, but that my supposition they might have used it in the Versomat processor is probably wrong.

HC110 syrup without water might make a decent 1st bath. Water might work as the 2nd bath. If the concentrate is too strong it could be "thinned" wich glycerol or glycol. Perhaps I should have used "tamed" instead of "thinned."

sanking · Jul 9, 2008

I have an article on two-bath development in the next issue of View Camera magazine, which should be out soon. The article is directed primarily to those who work with hybrid techniques, i.e. scan to print digitally, but some of the information in the article is relevant to work with 35mm and MF formats.

Sandy King

Paul Verizzo · Jul 9, 2008

Be sure to tell us when!

sanking said:
I have an article on two-bath development in the next issue of View Camera magazine, which should be out soon. The article is directed primarily to those who work with hybrid techniques, i.e. scan to print digitally, but some of the information in the article is relevant to work with 35mm and MF formats.

Sandy King

Then I'll have to find it....somewhere....somehow....

Photo Engineer · Jul 9, 2008

Two bath development is a chancy thing due to the varying thickness of film and the varying amounts of silver halide, not to mention the amount of iodide present. So, it must be fine tuned for every film to work properly. AFAIK, Kodak never used one. Any viscous developer probably used Sorbitol or Carboxy Methyl Cellulose, or mixtures of the two.

PE

sanking · Jul 9, 2008

PE,

Actually my own experience suggests otherwise. I tested several traditional emulsion and T-grain emulsion films and found that *most* of them developed to about the same average gradient, and same curve type, with the same time of development.

I did find one anomaly in the tests, though, and that was Ilford FP4+, a traditional emulsion type film.

What I have found to give very inconsistent results is water-bath development.

Sandy

Photo Engineer said:
Two bath development is a chancy thing due to the varying thickness of film and the varying amounts of silver halide, not to mention the amount of iodide present. So, it must be fine tuned for every film to work properly. AFAIK, Kodak never used one. Any viscous developer probably used Sorbitol or Carboxy Methyl Cellulose, or mixtures of the two.

PE

MarkL · Jul 9, 2008

I don't know anything about two bath developers, but I assume this topic is the most important for roll film users where contrast control is needed for some frames without greatly affecting others. For me, using sheet film, it would be useful too but wouldn't SLIMT (selective latent image manipulation technique) pre-developer bleaching work as well? Supposedly you can get several stops of proportional reduction without sacrificing shadows much.

Just curious about any differences in the approaches....

Mark

sanking · Jul 10, 2008

Two bath development gives automatic highlight compensation with an almost linear straight line curve. Highly unique and much superior to most compensating type developers.

Also, two bath development requires virtually no field notes as to exposure and contrast. You simply expose for the shadows and develop all films together. The developer does the rest, within established limits.

Sandy King

MarkL said:
I don't know anything about two bath developers, but I assume this topic is the most important for roll film users where contrast control is needed for some frames without greatly affecting others. For me, using sheet film, it would be useful too but wouldn't SLIMT (selective latent image manipulation technique) pre-developer bleaching work as well? Supposedly you can get several stops of proportional reduction without sacrificing shadows much.

Just curious about any differences in the approaches....

Mark

dancqu · Jul 10, 2008

sanking said:
Two bath development gives automatic highlight compensation
with an almost linear straight line curve. Highly unique and
much superior to most compensating type developers.

Also, two bath development requires virtually no field notes
as to exposure and contrast. You simply expose for the shadows
and develop all films together. The developer does the rest,
within established limits. Sandy King

Are there other than two bath developers
being marketed? Dan

Two bath film development queries

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