Thornton's Formula - Photos

[naruto]

I could not find a thread that had shots developed with the Thornton Formula, so here it is.

The Babbage Engine

Geared to Work

Moving Parts

Complex Interlinks

more to come.... 🙂

 

[FPjohn]

Nice photographs! There were several formuli....

 

[naruto]

Nice photographs! There were several formuli....

Perhaps I should have mentioned, I use the following combination:

Bath A -
Metol 6.5 gms
Sodium Sulfite 80 gms
Water to 1 Liter

Bath B -
Sodium Metaborate 12 gms
Water to 1 Liter

I reduced the Sulfite from the norm of 85 gms, as in the book Edge of Darkness, to increase the acutance effect. The Bath A inversion was 1 every min, and Bath B one inversion every 3/4 of the timing window.

I also developed a roll of Foma 100, but it looks like the negatives are fogged. It could be either because of passing through the airport scanner, or my timing is off (3.5 min in each bath).

 

[Tom A]

The Thornton Formula(s) work well with older type film. On"thin-emulsion" film I find that you have to let it "stew" for a bit longer in the B-bath. I suspect that it doesn't pick up enough of A to continue developing fully in B.
Some years ago I tried it with the venerable XX and it looks very good. It can create some fogging and I usually add some Benzotriazole to it to clear it.
Nice shots of the Babbage engine - as someone who does machining - it is pretty awe-inspiring to look at the complexity and the gearing. Hmm, would make one hell of a motor for a M2!

 

[naruto]

The Thornton Formula(s) work well with older type film. On"thin-emulsion" film I find that you have to let it "stew" for a bit longer in the B-bath. I suspect that it doesn't pick up enough of A to continue developing fully in B.
Nice shots of the Babbage engine - as someone who does machining - it is pretty awe-inspiring to look at the complexity and the gearing. Hmm, would make one hell of a motor for a M2!

Thanks Tom. This piece of info is good learning. 🙂 I'll try out 5 mins in each as a starting point.

I was staring at the Engine open-mouthed myself. To have thought up of such a system way ahead of anyone else fills me with awe.

 

[Tom A]

The A-bath in the Thornton is basically Kodak's D23 and you have some development taking place already in it. The B-bath accelerates the process further.
You can "balance" the development times by doing tests - run the film through the A bath for 5 min and keep the B to 3.5 minutes and see what happens. If it is still too thin - give it a bit more time in B.
2-part developers are very good for contrast control, but you need to "shoot" yourself in with it. Use up some film in trials and once you have negative/developer combination that works - just stick to it.
D23 type developers (Leica's 2 bath etc) are prone to excessive fog and you have to check which film works and which doesn't here. At least the weather is sunny and nice - so shooting tests are not a strain!

 

[venchka]

Search this forum for posts and images by user dazedgoneby. Steve uses Barry's two bath exclusively for medium format and 4x5. Great work I would add. Look around the 120 folder and large format areas. Steve told me that his method was 4.5 minutes in each with continuous agitation in a Jobo tank. Steve uses a lot of FP4.

Thanks for sharing. I will give Barry Thornton's two bath developer a trial run soon.

 

[naruto]

The A-bath in the Thornton is basically Kodak's D23 and you have some development taking place already in it. The B-bath accelerates the process further.
You can "balance" the development times by doing tests - run the film through the A bath for 5 min and keep the B to 3.5 minutes and see what happens. If it is still too thin - give it a bit more time in B.

Thanks Tom. The advice was invaluable.

For Foma 100, Bath A 5.5 mins, Bath B 6 mins, gives excellent results. The negatives have great "punch" to them and look very nice on the light table. Will put up some scans in a day or two. Finally, cheap film + cheap developer. Now to tackle the curling on the film.

Has anyone heard/used a hardening solution that helps stop film curl?

 

[dazedgonebye]

The Thornton Formula(s) work well with older type film. On"thin-emulsion" film I find that you have to let it "stew" for a bit longer in the B-bath. I suspect that it doesn't pick up enough of A to continue developing fully in B.
Some years ago I tried it with the venerable XX and it looks very good. It can create some fogging and I usually add some Benzotriazole to it to clear it.
Nice shots of the Babbage engine - as someone who does machining - it is pretty awe-inspiring to look at the complexity and the gearing. Hmm, would make one hell of a motor for a M2!

I keep reading and hearing that the subject formula is best for older films, but I haven't seen anything really to bear that out. Now, I haven't been at this all that long so I don't want to set myself up as any sort of expert. I frankly don't think I have a critical enough eye to tell the difference between Thornton's at 4 minutes or Thornton's at 5 minutes...at least not on rolls of film shot at different times and places with all the other variables involved.
Anyway...there are examples in "Edge of Darkness" of the formula used with TXP-320 that are very good. In fact, if I remember correctly, Thornton stated in that book that "his" formula was just a tweaking of older formulas to make them more appropriate for modern films.
Here are a couple of my own 4x5 TXP-320 films done in Thornton's.

Again, I'm not being sarcastic when I say I am no expert. I was drawn to Thornton's because I'm lazy and sloppy and highly distractable. I needed something that would be forgiving of time and temperature. I've gotten results good enough at least to make me happy using it with Efke 25, Efke 50, Efke 100, PanF, FP4, TXP-320 and Tri-X. I've used it on 35mm, 127, 120 and 4x5 film as well. All without regard to temperature or precise timing, all at between 4 and 4.5 minutes (ok, I once went to 6 minutes on the A bath because I forgot).

 

[Tom A]

TXP 320 is a good example of "vintage" film. Interesting to hear that the Thornton works so well with the "thin" films like Efke too. Haven't tried it - but will.
At the moment I am shooting XX (again) and once I have 10 rolls exposed I will do a Thornton "run". In between showers I am also shooting a dog's breakfast of 100 asa film (Acros/Tmax 100/Agfa Scopic X-ray film and it might try that too in it).
I think the biggest problem is to control base-fog with D23 derivatives.

 

[dazedgonebye]

TXP 320 is a good example of "vintage" film. Interesting to hear that the Thornton works so well with the "thin" films like Efke too. Haven't tried it - but will.
At the moment I am shooting XX (again) and once I have 10 rolls exposed I will do a Thornton "run". In between showers I am also shooting a dog's breakfast of 100 asa film (Acros/Tmax 100/Agfa Scopic X-ray film and it might try that too in it).
I think the biggest problem is to control base-fog with D23 derivatives.

Showing my ignorance. I thought of TXP as a modern film, since it replaced Tri-X in 4x5. Bad assumptions I guess.

I wonder about base-fog. I can't say I've seen it, or perhaps do not recognize it. On the other hand, could that be why it seems to work well in controlling contrast in PanF.
I often get comments that the contrast on my PanF stuff is more controlled then others experience.

PanF

 

[venchka]

Steve,

I have some 6x7 TXP-320 negs. from 1973. I don't know if that emulsion is the same as the one made today. Nice film. I liked it then & I like it today. My last roll of B&W in the Pentax was TXP-320.

 

[Tom A]

If my memory serves me right (it rarely does!) - the TXP 320 was noted as a portrait film and had a slightly different emulsion surface that allowed for spotting and correction directly on the surface.

 

[venchka]

That's how I remember it too, Tom.