Just want to nail it -- add the photoflo at step a i.e. as part of solution A or add it just in the middle of step c i.e. before draining.
Sorry to trouble you again.
Dennis Ng
Just want to nail it -- add the photoflo at step a i.e. as part of solution A or add it just in the middle of step c i.e. before draining.
Sorry to trouble you again.
Dennis Ng
Many thanks Sandy! That is exactly the kind of starting point information I need. I also develop for scanning and shoot roll film in 135 and 120.
I can certainly have the A and B solutions at 75°F when they are poured in the Jobo drum or tank. The temperature will rise a little during the 5 minutes of film contact. I can adjust time and dilution accordingly.
A friend of mine spent 2 years in Peru on a dig. No electricity. No temperature control. He used Diafine.
Off to order some Pyrocat-MC.
Wayne
Deep in the darkest heart of the North Carolina rainforest.
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For discussion and information about carbon transfer please visit the carbon group at groups.io
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Many thanks!!!
A bit of clarification:
I can get my chemicals to any temperature I choose. The problem becomes maintaing that temperature in the Jobo drum during development. If I start at 68°F (or even less), the temperature of the developer rises at least 4° in the first 3-4 minutes of development when the ambient temperature is 77°F-79°F. It has been so hot this summer that the A/C won't cool my apartment below 77°F. At that temperatue, my times are getting uncomfortably short.
Wayne
Deep in the darkest heart of the North Carolina rainforest.
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Thunking about blue ice bag. Thinking about trying 24c (75f) setting of jobo cpe/CPA (but not atl-1500 as hard to control external per-soak). Instead , use water pre-soak from bottle in the jobo water bath when it reach 24c after jobo warm up the blue ice bag in the water bath.
Then only the washing would be done at 29c.
Do you think it would work?
I would not worry about ambient temperatures when processing in a Jobo with two-bath Pyrocat. The mechanism of development itself serves to limit the range of contrast even with variations in temperature. I would just use a pre-soak at the temperature of your Solution A and not worry about ambient temperature. And temperature makes even less difference in Solution B.
So basically if the ambient temperature causes a rise of a few degrees of the solutions during the course of development this will not change final negative contrast very much.
Sandy
For discussion and information about carbon transfer please visit the carbon group at groups.io
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Wayne
Deep in the darkest heart of the North Carolina rainforest.
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I hope a little more enthusiasm for Divided Pyrocat is not unwelcome. This post prompted me to perform an experiment: a photo made under mid-day Sun on a cloudless day - something I haven't done with a View Camera in decades, if ever.
With ordinary methods of exposure and development, adequate detail in both the shadows and high values would have been impossible. The shade areas would have been black and lifeless, or the sun-lit wall would have been white - but it was trivial with Divided Pyrocat.
I simply metered the shadow area and placed it on Zone IV. The high values fell way off the scale, but the 2-bath development process took care of that. The shadow area has full separation - a remarkable feat - as do the high values.
Sandy's suggestion of adding a few grams of Photo Flo to Solution A, has worked wonders: I now get perfectly even development.
Massachusetts, 2010
Sinar P, 300mm Fujinon A
4x5 HP5+, Divided Pyrocat HD
Last edited by Ken Lee; 5-Sep-2018 at 16:50.
I've been using Diafine for all of my 4x5 development but have been considering giving a pyrocat version a try. I develop in a HP Combi-Plan daylight tank.
Is it possible to use that tank or do I need to go with something else? How much agitation would be needed?
Thanks!
William
4x5 and a Tessar is heaven
"I beg to dream and differ from the hollow lies..." Green Day
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