Thornton's Two Bath

[blackmelas]

blackmelas submitted a new resource:

(there was a url link here which no longer exists) - Thornton's Two Bath

BATH A
Metol- 6.25gr
Soduim Sulfite- 85 gr
Water to make 1 liter

BATH B
Sodium Metaborate- 12gr
Water to make 1 liter

ca. 3 min each bath iso 50 films
ca. 4 min each bath iso 100 films
ca. 5 min each bath iso 400 films

The late Barry Thornton reformulated Stoeckler's Two Bath recipe for thinner modern films. Comments on this?

Do not presoak or rinse between baths. Agitate every minute or more in bath A then empty. Pour in bath B smoothly and simply give a rap on the counter to dislodge...

(there was a url link here which no longer exists)

 

[John Bartley]

The late Barry Thornton reformulated Stoeckler's Two Bath recipe for thinner modern films. Comments on this?

From what I've read, Stoeckler, Thornton and Adams (likely many others also) experimented with variations on Kodak D23. I use the Adams variant of D23 which is 7.5/100/1litre for A and 10/1litre for B. I'm using "20 mule team" borax for the B bath and it works fine. I also presoak for two minutes and my films are FP4+ and PlusXAero in 4x5 and 8x10. This (the D23) stuff lasts forever. I'm currently using 8 month old D23 and it's working fine. My times for PlusXAero rated at iso10 are 5 minutes in A and four minutes in B. It's been a while for FP4+, so I don't remember now, but 4+4 rated at iso100 come to mind

 

[Gerald Koch]

My take on this is that he was merely tweaking the Stoekler formula for the contrast that he wanted. It had nothing to do with old/new, thick/thin films.

 

[blackmelas]

Yes it does seem as if they are closely related but he did mention that his motive was an update of Steockler (which is D23 for 35mm?). In Edge of Darkess, Thornton said that he lowered the sodium sulfite to increase sharpness slightly in response to modern finer grain films. Then because modern thinner film soak up less developer he changed from borax to more active and alkaline bath B with Sodium Metaborate.

I'm only starting to learn some of this, so be gentle if I read wrongly...
Best regards,
James

 

[buze]

I have been using this dev for a couple of months, I really like it. It's next to impervious to temperature ("around 20C" is enough) !
I do presoak the film; it's not recommended in the article, but with the dyes in films poluting the 2 baths, they become dreadful very quickly; the presoak gets rid of most of the dyes.

Sheet film doesn't seem to need agitation in B, but 120 film /in steel tank/ do need an inversion every minute or so, otherwise the film doesn't seem to clear properly (fog in the middle). I've seen reports saying that Paterson tanks do not exhibit the problem.

Otherwise it delivers exactly as promised, nice fine grain, and a really great range of tones, most especialy in high contrast scenes...

 

[Tom Hoskinson]

Yes it does seem as if they are closely related but he did mention that his motive was an update of Steockler (which is D23 for 35mm?). In Edge of Darkess, Thornton said that he lowered the sodium sulfite to increase sharpness slightly in response to modern finer grain films. Then because modern thinner film soak up less developer he changed from borax to more active and alkaline bath B with Sodium Metaborate.

I'm only starting to learn some of this, so be gentle if I read wrongly...
Best regards,
James

Kodak D-23 (Published Formula Copyright by EK 1941) was one of the results of Kodak's motion picture developer R&D effort that started in the early 1900s. Kodak D-76 (1927) was an earlier result of this R&D effort. Many other manufacturers including Agfa and Ilford marketed formulations that were very similar to D-23 and D-76.

I started using D-23 to develop Ilford Pan F, Kodak Plus X, Tri-X and Panatomic-X 35mm film in the early 1950's. I quickly determined that I liked D-23 best diluted 3:1.

I also started using D-23 as a 2 bath developer (the Ansel Adams version) in the 1950s.

 

[blackmelas]

Tom, What is it about the 1:3 dilution that you like?

 

[Tom Hoskinson]

I like the combination of acutance and tonality that D-23 gives when diluted 3:1 vs undiluted D-23. D-23 diluted 1:1 is my second choice. I use the diluted developer as a one-shot.

 

[lee]

I have also used Microdol-x and metaborate as a two bath and made very compensated negs as Microdol-x is a second cousin to D-23 as near as I can see. In my mind it is a very good solution to reciprocity failure problems. I would recommend that at the time of shooting that one consider this development option and give plenty of exposure to the neg or roll in question. That will support the shadows values.
lee\c

 

[Harry Lime]

I've been using Thornton's 2-bath for about 2 months now with Tri-X @ 400 and it's the greatest thing since sliced bread.

I've basically abandoned DD-X, except for Delta3200 and pushing Tri-X.

 

[davekarp]

In Edge of Darkness, Thornton gave the formula with 6.5g / liter of Metol, rather than the 6.25g / liter given in earlier formulations. I E-mailed him before he passed away, and he told me that the 6.5g / L version was his preferred version.

 

[oldglass]

A few questions specifically about mixing the chemicals:

1. Do I basically just measure, pour and stir? or do I need to boil/warm the water, etc.?

2. After I mixed according to the formula (in the first post of this thread), do I end up with concentrate solutions or working solutions? if concentrates, how much dilution is recommended to make the actual working solutions?

Sorry for the basic questions, but I sure can't get the answers easily by searching online.

 

[Dwane]

A few questions specifically about mixing the chemicals:

1. Do I basically just measure, pour and stir? or do I need to boil/warm the water, etc.?

2. After I mixed according to the formula (in the first post of this thread), do I end up with concentrate solutions or working solutions? if concentrates, how much dilution is recommended to make the actual working solutions?

Sorry for the basic questions, but I sure can't get the answers easily by searching online.

1. Yes - measure, pour and stir. Use warm (125 deg.F, 52 deg.C) distilled water.

2. You end up with working solutions. Use the solutions just as suggested by blackmelas in his first post.

 

[corsaaaire]

Hi all,

I did read Edge of Darkness and tried Barry Thornton two baths developer on HP5+ EI400 in 120 format last week end.
What would happen if i let the film longer or less time in each bath ? Would the highlights raise higher like in a normal developer ?

What time of development do you suggest me please for HP5 rated at 400, and for 200isos ?

Best regards,
Lionel

 

[Alan Johnson]

There is some info for the similar Stoeckler developer:
www.largeformatphotography.info/twobath/
I don't think similar test results are avalable for Thornton's.

 

[corsaaaire]

Thanks for your answer Alan.

I had tried Thornton two baths with FP4+@100 and i like much more than with HP5+. The tones are nicer.
I still find more grain than with ID11, should i add more sodium sulfite like in D-23 formula ?

I had some uneven development on my negs if i don't agitate any of the two baths.

On the link you provided, it is said to change time in first bath only if i want to increase or decrease global contrast, it sounds logical, whereas Thornton suggested to put more or less sodium metaborate in second bath to achieve N-1 to N+1 development.
Have you guys tried one of these methods ? Do you have some times for iso 100 or 50 i should start from for my tests?

 

[Alan Johnson]

My measured results were only for Delta 100 developed in Thornton's with 12g/L metaborate for 4 min + 4 min 70F as per Edge of Darkness (ED), agitating 2 initial inversions then 2 inversions/min. This gave EI=80 ,average metering,sun/shade.
In ED p94 sodium sulfite was reduced to cut down grain dissolving activity and increase sharpness so it would be expected that increasing sulfite again would have the opposite effect.
The link indicates longer times in A increase contrast,ED p95 notes that increasing metaborate does the same.
At a guess it seems quite likely that EI=50 or EI=100 could be obtained by varying the time,at least with Delta 100 and quite likely FP4+.If the contrast is not satisfactory it might be adjustable by varying the alkalinity,metaborate concentration, as Thornton suggests,only experiment can tell if speed and contrast can be balanced in this way, I have not seen results from others on this.

 

[Mark Booth]

Dave Karp is right in his observation that Barry's revised formula called for Metol 6.5 grams instead of 6.25 grams. I had dialogued with Barry on a regular basis for about 3 1/2 years prior to his untimely death. In fact, we were talking about planning some time together doing some photography in the UK. Photography really lost a master photographer and passionate teacher to all.

I have developed many hundreds of rolls of film with the Barry Thornton 2-Bath developer over the years, and have found it particularly useful for roll film processing. (IDEAL FOR: many images with variances in exposure or contrast scenes, or processing in one large tank several different film types are made easy with the 2-Bath process).

While most of my work is now done with sheet film—pyro and brush development by inspection method, I find Thornton's formula hard to beat particularly for anyone not requiring (or desiring) a tanning and staining developer. If one desires a little added sharpness without inducing grain, one can add 6-9 grams of sodium ascorbate (vitamin-C buffered) to bath A and develop as usual with little change in contrast. But, in reality this developer is just so nicely balanced that tweaking it too much defeats its purpose in my way of thinking. Simplicity is such an important key in the quality and elegance of a good developer. Simplicity of formulation also allows one to learn more easily the behavioral characteristics and cause relationships (influences) between developing agents and constituents. While I like the use of sodium metaborate because of its balance with contrast and grain combination, one can use borax for finer grain or sodium carbonate for increased sharpness. But for all intent and purposes, all images will work very well with sodium metaborate as the activator in bath B.

 

[Jonathan R]

This is my one and only developer these days. I started with Tetenal's Emofin, but after some years on that with 35mm Tri-X I found myself disatisfied with a mid-tone muddiness. So I switched to the Thornton 2-bath. I like it best with HP5+, second best ith FP4+, but it also works very nicely with Tri-X and Delta 100. I see no reason to search further.

 

[Iain Maclachlan]

Is it possible to replace the sodium metaborate in bath B with Borax, if so what would be an equivalent amount?

 

[grahamp]

The Large Format link above will give you an initial recipe for a Borax second bath - 10g/l. However you will likely find that this is not alkaline enough for modern films. I find the sodium metaborate bath B much better.

 

[Iain Maclachlan]

Thanks. I will be shooting Fomapan 100 Classic so it will be interesting.