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View Full Version : Dilute Pyrocat times at high temps?



CreationBear
21-Sep-2018, 08:28
A newbie question for y'all: I'm gearing up to shoot and process some 4x5 FP4+, but
a quick recce of the community darkroom I've joined revealed that the water/ambient temperature I'll be working with is 75-77 degrees.

I understand that I'll need to cut development times by up to a third for "normal," intermittently agitated runs, but was curious if I needed a similar fudge factor if I wanted to try semi-stand (e.g. "EMA") with 1:1:150-200 Pyrocat, given that the chemistry "self-regulates" (if I understand correctly) as the reagents chug on toward exhaustion.

Any thoughts appreciated--it might be that I might need to take steps to get to 68-70 before getting too far down this road, but since the workspace is a "commons," I'm hesitating before rolling in with a bag of ice.:)

Alan9940
21-Sep-2018, 11:01
Using Pyrocat-HD up to 80F is not a problem; I typically run my developments in that temp range because my ambient darkroom temp hovers around 80F for many months during the warm spell (desert southwest, USA). You can do "regular" development at 1:1:100, minimal agitation, stand, EMA, whatever...but, it all requires testing to determine your own parameters.

CreationBear
21-Sep-2018, 11:27
my ambient darkroom temp hovers around 80F for many months during the warm spell (desert southwest, USA).

At least it's a dry heat--more than we've been able to say this summer here in the Southeast.:) Thanks for the insights--I hear what you're saying about "testing" as well...I'm finding the number of variables to juggle a bit daunting, but hopefully a trail of breadcrumbs will emerge.