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Steven Ruttenberg
1-Nov-2018, 19:32
Potassium ferricyanide, Potassium bromide and potassium dichromate for pulling negative. I am going to experiment with this and by combining with 2-bath Pyro at. And also compare to using Tmax developer, HC-110 and SLIMT with these two developers and to the two developers by themselves and I might throw in standard Pyro at HD. And if I am feeling really punky once I find a good method from this see how semi-stand and stand processing enhances or inhibits the results.

I plan to post the developed negatives for all to compare.

koraks
2-Nov-2018, 00:56
I hope you bought potassium ferricyanide and not ferrocyanide!

Steven Ruttenberg
2-Nov-2018, 11:03
ferricyanide

1 x Pyrocat HD Dry or Liquid
(Size: 01-5083 50 lt Liquid)
1 x Potassium Dichromate*(Class 6.1) (Bichromate)(§) (GROUND UPS ONLY) DEA FORM REQUIRED / Choose ups ground shipping at checkout
(Size: 10-1000 1 lb)
1 x Potassium Ferricyanide
(Size: 10-1010 1 lb)
1 x Potassium Bromide
(Size: 10-0930 1 lb)

Doremus Scudder
2-Nov-2018, 11:05
Steven,

I'm really curious as to what shooting situations you have in mind that would require a combination of SLIMTs, two-bath compensating development and/or semi-stand development.

I've been using SLIMTs for extreme negative contractions for years and get a good N-4 or even N-5 with the right strength SLIMT bath (using ferri and bromide only - what's the dichromate for anyway?) and normal or N-1 development times. That said, I only rarely find myself in situations that need more than N-2. Heck, those situations are rare enough, and I've got printing controls as well (lower contrast filtration or grade 1 paper and soft working developers) that will allow me to print an N-4 situation developed to N-2 (i.e., two zones too contrasty for grade 2 paper) just fine.

I'd really like to know how you're planning to apply all these contraction techniques and for what purpose. I can't imagine when I'd ever need so much contraction...

Best,

Doremus

Steven Ruttenberg
2-Nov-2018, 11:16
Part of it is just to learn from the experiements, but the idea is to use the slimt for the highlights and then see how the 2-bath can if possible further help the highlights while maintaining shadow detail. I shoot a lot of extreme scense, like directly into the sun at the Grand Canyon. You generally have a choice of exposing the canyon properly or the sky properly, but almost never both. Even with a grad nd you are hard pressed to get there. In addition to see how the different techniques compare to just simply developing in different developers normally and by pulling with no additional techniques employed.

The potassium ferricyanide and bromide is for contrast wise contraction whereas the dichromate is for speed wise bleaching for pulling of overexposed film. This should allow for some greater capability in the highlights as well which will be overexposed for sure when exposing the canyon properly as there is usually a 10 stop difference in the canyon floor and the sky with sun in it, like sunset/sunrise. Also on backlit clouds which can be annoying as hell when all else works and they are blown out. If you measure the canyon floor at zone v, then your up to zone XV for the sky. My first experiment with 2 bath I posted after exposing canyon floor properly and I was able to pull off the sky detail as well.

So, in reality I do not know if combining will work, but I am going to try and it is cheap to do so and I sorta like this hands on part of the photography.

Hopefully, this does not sound confusing. Just experimenting to see what is possible or not possible.

Doremus Scudder
2-Nov-2018, 11:32
Steven,

I wish you luck. I've found that there's no free lunch when it comes to contractions. Yes, you can use a number of techniques to get the negative contrast range to fit your chosen paper, but in situations like you describe, the result is often flat and muddy mid-tones.

I've gone the other way many times, intentionally making a too-contrasty negative and then taming it later with print manipulations - all to try and save the separation in the lower and mid-tones.

Do post your results here; I'm always interested in finding more tools to deal with extreme scenes.

Best,

Doremus

Steven Ruttenberg
2-Nov-2018, 11:39
Steven,

I wish you luck. I've found that there's no free lunch when it comes to contractions. Yes, you can use a number of techniques to get the negative contrast range to fit your chosen paper, but in situations like you describe, the result is often flat and muddy mid-tones.

I've gone the other way many times, intentionally making a too-contrasty negative and then taming it later with print manipulations - all to try and save the separation in the lower and mid-tones.

Do post your results here; I'm always interested in finding more tools to deal with extreme scenes.

Best,

Doremus

I hope to post up my results. First thing I gotta find a contrasty scene with ultra high dynamic range, then take about 20 frames or so all at the exact same settings. Preferably within 5 minutes or less, then hopefully I will have enough to do the experimenting I want. The hard part is first finding what dilution, time for slimt that provides best results before going on to combining with 2-bath. If one isn't right then none is right.

I use Tmax100/400, delta100 and HP5/400. For color negatives really only have 1 option which is slimt combined with possibly the standard approach to pull processing.

Andrew O'Neill
2-Nov-2018, 12:20
David Kachel's bleach and redevelopment technique, as far as I know is still the best way to handle extreme contractions and not lose anything in the shadows... Sadly it does not work for stained negatives, as I found out years ago. In cases where extreme reductions are necessary (rarely), I'd develop in Xtol 1+1 then use Kachel's method. Nowadays, I use two-bath pyrocat-hd.

Steven Ruttenberg
2-Nov-2018, 14:54
Yeah, I am using the 2-bath currently. I was going to bleach first then use 2-bath to develop. Will find out what works, either will get a great result or something that looks like a Van Gogh.

koraks
2-Nov-2018, 15:32
What is the purpose of the dichromate? The only things I can think of in the context of film nefatives are intensification and non-rehalogenating bleach. Watch out with that stuff, it's a known carcinogenic. Don't get it on your skin and certainly make very sure not to breathe it in.

Steven Ruttenberg
2-Nov-2018, 21:36
I won't, safety is number 1 priority. It is a speedwise bleach for pull processing according to Kachel's write up on bleaching.

koraks
3-Nov-2018, 01:26
Hm, I'll have to read some more of Kachel's writings. I wonder why he would choose a dichromate process despite its obvious drawbacks (toxicity, stain).

Steven Ruttenberg
3-Nov-2018, 08:45
This is all new to me. Just trying to find a solution to the challenge of shots I like to make.

Steven Ruttenberg
6-Nov-2018, 12:00
So, following the mixing instructions for just the Potassium Ferricyanide to get a feel for the dilution strength, I followed Kachel's recommended formula for a starting working solution and came up with a mixture taht of .45gms PF to 450ml of water (if I wanted to mix it every time I used it. Of course I would still need to figure the amount of Potassium Bromide to prevent fogging) In reality though, I will just mix the Full strength Stock solution as he recommends, then from there the stock solution which then becomes the working solution where you play with the dilution to get what you want prior to adjusting times to fine tune. I am surprised at how little Potassium Ferricyanide is actually used in this process. Wish developer was as cost effective :D

I am going to be using Tmax100 and HP5400 to start with. Has anyone used this technique with those films? My developers are listed above.

My tripple beam balance will be here this week I hope. Good thing I paid attention in my college chemistry class!