Thornton's Two Bath

[blackmelas]

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 air bubbles. I give at least one inversion at the mid point in bath B.

Thornton claimed you could get at least 15 rolls out of the A and B solutions (this I've tested to be true though the B had a putrid smell at the end) and that bath A lasted for up to a year (Have not tested this).

my personal times are 2:15 in each bath for Maco ORT25, Efke 25; 2:45 in each bath for Pan F; and 3:45 in each bath for FP4+.

[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.