pyrocat hd: stain intensity and dilutions with stand dev

crypt47 · Mar 12, 2019

Good day, everyone. I'm taking first steps with pyro (35mm, stand dev) but can't find proper info for general questions. Cause I don't understand the meaning of part A and part B, I can't understand how to use proportions to manage contrast. Also today's morning I've got too much base stain with stand development (1:1:600). (No edge effect btw.) Instead of changing time, would prefer to change proportions.

john_s · Mar 12, 2019

Sorry I have no detailed experience with stand developing. Just wondering why you aren't just using standard dilution and times. Pyrocat-HD used in this way is really very good.

GLS · Mar 12, 2019

Part A contains the developing agents. Part B is simply a solution of potassium carbonate, which provides the correct pH to enable development. See: http://www.pyrocat-hd.com/html/mixing.html

Also I agree you should initially stick to the dilution/times recommended by Sandy: http://www.pyrocat-hd.com/html/times.html

As an example guideline: I develop Acros (at EI 80) in 1:1:100 at 21.5 C (70F) in Paterson tanks using minimal agitation (but not stand). The results are stellar.

crypt47 · Mar 12, 2019

GLS said:
Part A contains the developing agents. Part B is simply a solution of potassium carbonate, which provides the correct pH to enable development. See: http://www.pyrocat-hd.com/html/mixing.html

Also I agree you should initially stick to the dilution/times recommended by Sandy: http://www.pyrocat-hd.com/html/times.html

As an example guideline: I develop Acros (at EI 80) in 1:1:100 at 21.5 C (70F) in Paterson tanks using minimal agitation (but not stand). The results are stellar.

Thanks, for part-a/part-b explanation. Do you know what influence the stain? Sticking with classic recommendations is not suitable because my whole system differs.

crypt47 · Mar 12, 2019

john_s said:
Sorry I have no detailed experience with stand developing. Just wondering why you aren't just using standard dilution and times. Pyrocat-HD used in this way is really very good.

I'm using my own system for film dev process with low agitation. My temperatures are also significantly different (lower). And please don't tell me I can't (or shouldn't) do it. It works for the last few years.

esearing · Mar 12, 2019

Pyrocat HD Part B influences developer speed and color/base fog. 1:1 produces more stain than 3:2 ratio but also requires more time. I use 3:2:500 and have barely any stain. Be careful going more dilute than 1A/B to 250 parts water, and less than 2A:1B since you will not have enough developer to do the job. My normal is 3A 2B 500W for minimal base stain. 3:3:500 shortens time or increases contrast, but has more base fog.

crypt47 · Mar 12, 2019

esearing said:
Pyrocat HD Part B influences developer speed and color/base fog. 1:1 produces more stain than 3:2 ratio but also requires more time. I use 3:2:500 and have barely any stain. Be careful going more dilute than 1A/B to 250 parts water, and less than 2A:1B since you will not have enough developer to do the job. My normal is 3A 2B 500W for minimal base stain. 3:3:500 shortens time or increases contrast, but has more base fog.

Aha! That corresponds to my tests. Ok, I'll be careful. What about the opposite limits? What if I go with higher concentration? I've head people did two bath: first soak in 10A 300W and then activate with part B. I have an impression that grain stays approximately the same (comparing to other developers)?

koraks · Mar 12, 2019

Prolonged development as in a stand regime will always result in higher general stain due to oxidization of the developer. This may however not be an issue as you can generally print through it very easily.

Andrew O'Neill · Mar 12, 2019

Personally, I do not recommend full on stand development. I've had disastrous results with many films (large format). Semi-stand is safer and gives very similar if not identical results. I don't mess with A and B. It's always 5ml each in 1200ml water. Film gets an hour with 5 sec agitation every 15 minutes. 21C. I haven't noticed any increase in stain.

esearing · Mar 13, 2019

crypt47 said:
Aha! That corresponds to my tests. Ok, I'll be careful. What about the opposite limits? What if I go with higher concentration? I've head people did two bath: first soak in 10A 300W and then activate with part B. I have an impression that grain stays approximately the same (comparing to other developers)?

More developer = shorter times or more contrast. Two bath is a different animal. I think you need a really contrasty scene to resort to two bath, and even then you may get uneven results. I like longer dilute development schemes with a minimum of 5 minute agitation intervals for more control. Do a comparison using 2 sheets of the same shot. Another advantage of long dilute development schemes is that the 20-30 seconds it takes to fill and dump become less impacting at 20+ minutes when compared to 6 minutes, but temperature fluctuation is another factor to be aware of.

crypt47 · Mar 13, 2019

esearing said:
More developer = shorter times or more contrast. Two bath is a different animal. I think you need a really contrasty scene to resort to two bath, and even then you may get uneven results. ...

Well, I didn't mention it, but the reason I picked up Pyrocat HD was exactly this: a really contrasty scene which I screwed up with every other thing I tried. Bright sun, snow everywhere looked blank despite I needed to show the volume of snow sculptures. Also people.

crypt47 · Mar 13, 2019

esearing said:
...but temperature fluctuation is another factor to be aware of.

in my case (my special system, I've mentioned) temp, water quality and other consistency factors are very well controlled, no problem.

crypt47 · Mar 13, 2019

I'm mostly on track now. Will make tests with two bath by myself.

crypt47 · Mar 13, 2019

koraks said:
Prolonged development as in a stand regime will always result in higher general stain due to oxidization of the developer. This may however not be an issue as you can generally print through it very easily.

Got some problem with printing, so temporary I do a lot of scanning.

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