Divided Pyrocat HD 120 development guidance

[Ozzietx]

I have exposed some Acros 100 120 film in some pretty contrasty situations, and want to try
divided pyrocat on the film. I am a little confused about doing this though based on the info I have seen.

My primary concern is uneven development. I plan on using my usual nikor tank.

It seems that I have read that doing divided pyrocat in a tank can lead to uneven development if developed
like I would normally do. I don't have the room to just dunk the reel into the developer in total darkness.

Is it possible to get even development by using a tank like I would normally do.

By normal, I usually give a 3 minute soak in water, then I pour the water out and add the developer.
If I do this with solution A with a few drops of photo flo, will I get uneven development?

The images are duplicable if I botch this up, but if there is no way to actually do this with the equipment I have, I will just use my normal development techniques.

 

[jim appleyard]

I've done divided PCat with tanks and it works fine, no uneven developement I don't know about using Photo-flo. I've never done it, but the jury is still out on whether it's a good idea.

If you like, try a test roll first, see how it works for you.

 

[Chris Livsey]

Given your concerns, understandable, on the results and I am all in favour of experiments what are you looking to gain over using the Pyrocat HD straight? Unless you run another roll, exposed identically, in straight developer you will have no objective comparison.
I think the pre-soak may be "better" at 5 mins ( I use some agitation half way) but I have never seen a difference using a photoflo or equivalent. ( and yes on a second roll exposed under the same conditions and developer )

 

[Ozzietx]

Chris, it is my understanding that using divided pyrocat will give me more tonal range compared to normal pyrocat.

Maybe my understanding is not correct.

 

[Gerald C Koch]

A presoak with a divided developer is not a good idea. Each time it is done it dilutes bath A a bit. Besides it is unnecessary as no development should take place in bath A.

 

[Chris Livsey]

A presoak with a divided developer is not a good idea. Each time it is done it dilutes bath A a bit. Besides it is unnecessary as no development should take place in bath A.

Sandy King does recommend a pre-soak with this method and if anyone is an authority on this topic he is, but he does say it may not be necessary and does also say it should be well drained if used. That effect I think is exaggerated as even if say 10ml is retained, surely an overestimate, in a 5 reel tank that is swamped by the 1500mls (approx) of developer, 0.7% dilution, I doubt I mix to that level of precision in the first place.

http://www.pyrocat-hd.com/html/TwoBathPyrocat.html

Chris, it is my understanding that using divided pyrocat will give me more tonal range compared to normal pyrocat.

Maybe my understanding is not correct.

No it is, my bad, as we are supposed to say now, I had looked at it previously as I am a fan of two bath, in particular TD-201, yet another Beutler type derivative from Anchell and Troop.
I recall when refreshing my memory why I have not used Pyrocat HD divided it is the line from Sandy King describing the process : " Then, when the film is transferred to the second solution, with its much higher pH, local exhaustion of the reducer in the highlight areas is total, and almost instantaneous. " My bold of course, I am uncomfortable with that and IMHO it probably accounts for reports of uneven development as with a conventional tank that is in daylight it is impossible to achieve fluid addition that is rapid and even.

I am still of the opinion you should run a test on the same exposures under both conditions, but certainly wish you luck.

BTW my 5 mins pre-soak, Sandy quotes 3 mins, comes from Ilford who recommend it when soaking to remove the surfactant incorporated in their emulsion for rotary processing where the frothing can be an issue. I have quoted the source previously.

 

[Gerald C Koch]

Both Kodak and Ilford are essentially neutral when it comes to a pre-soak. I had not even heard of it before joining APUG. I personally think that we have the "chicken soup effect" here. In other words despite many Jewish grandmothers who advocate its use it really doesn't do anything.

 

[Chris Livsey]

In other words despite many Jewish grandmothers who advocate its use it really doesn't do anything.

Now I would dispute that, purely from the medical field in which I work. There is a most definite placebo effect it exerts a psychological benefit to the patient photographer rather than for any physiological practical effect if administered with sufficient conviction.
I suspect the Jewish grandmothers knew that, if delivered in a convincing way the benefit can be clearly demonstrated. This is one of the primary reasons why in clinical trials those in patient contact are blinded to which arm of the trial their patient is on, active or placebo (more usually these days the current gold standard treatment as giving nothing is rather ethically frowned on now) to avoid influence.
I was involved in a placebo trial recently and we had three patients removed from the trial early for unacceptable side effects reported by the patients and considered so serious they were withdrawn by their physicians, you know what's coming, yes all three, when the code was broken, were on placebo.

This is why, way up there, I suggested a parallel film exposed under identical conditions in the usual developer to compare, with only the experimental film and high expectations it is likely the result would be biased positively especially as the evaluation was to be subjective.

Bottom line, I am as unconvinced as you by pre-washing/soaking but I do use it where it is recommended by workers who have exhaustively tested their work and I am using their process, I have seen no work that demonstrates detrimental effects and as you say both Ilford and Kodak are neutral would tend to confirm that.

And finally, before we have the inevitable angels on a pin comment from somewhere, the
density of angels dancing on the point of a pin is dependent on the assumed mass of the angels, with a maximum number of 8.6766*10exp49 angels at the critical angel mass (3.8807*10exp-34 kg).

Quantum Gravity Treatment of the Angel Density Problem
by Anders Sandberg
SANS/NADA, Royal Institute of Technology, Stockholm, Sweden

 

[Andrew O'Neill]

I don't bother with a presoak. Put a few drops of Photo Flo in the part A. Pour in and agitate continuously. Pour out. Pour in part B quickly. Agitate the entire time. Photo Flo not necessary for part B. I do 6 minutes in both A and B. I dilute both parts 1+20. Good luck.

 

[Ozzietx]

Thank you all for your input. I really appreciate that.

 

[Gerald C Koch]

In my family my grandmother always made beef tea (a type of beef broth) when someone was sick. A large piece of soup beef was simmered for hours. Any solids and fat were strained off and a bit of salt added. The idea was to give something nutritious but gentle on the stomach.