waynecrider
Subscriber
I just started using the metol version of Pyrocat with Na Carbonate, 20:100:940. Can anyone quote 4x5 sheet capacities for this or the original formula.
I use 435 ml for an 8x10 sheet in the 2:3:100 concentration, so conceivably you could use 110 ml per 4x5 sheet. If I were you I would go with at least 200 ml per 4x5 sheet to avoid exhaustion and/or streaking.waynecrider said:I just started using the metol version of Pyrocat with Na Carbonate, 20:100:940. Can anyone quote 4x5 sheet capacities for this or the original formula.
Jorge said:I use 435 ml for an 8x10 sheet in the 2:3:100 concentration.
Drop a line to Clay Harmon, he uses the Jobo drums with ULF film. He would be the best one to tell you the advantages of using tubes with the big negs. Since I do all my 12x20 developing on trays I would not know how well the tubes would work.colivet said:Jorge, I am amazed at how little chemistry you use. I didn't know using tubes would save so much chemistry. Me, I have never bothered with 8x10, because 1 liter is still very cheap, but I have a 12x20 on the way to me and I am preparing to minimize waste of chemistry.
I have built my own trays out of acrylic to fit the 12x20 with some room to spare for fingers. One question arises now: Do you think using tubes would allow great saving of chemistry on large negatives.
With the trays I have built I expect to use 3 liters of chemistry. As far I as know, no one makes trays for 12x20 so most people use 16x20 trays. True?
I suppose I have to balance the savings with the fact that I am used to inspection developing. I don't think tubes will allow for that. Right?
Thanks,
colivet said:Jorge, I am amazed at how little chemistry you use. I didn't know using tubes would save so much chemistry. Me, I have never bothered with 8x10, because 1 liter is still very cheap, but I have a 12x20 on the way to me and I am preparing to minimize waste of chemistry.
I have built my own trays out of acrylic to fit the 12x20 with some room to spare for fingers. One question arises now: Do you think using tubes would allow great saving of chemistry on large negatives.
With the trays I have built I expect to use 3 liters of chemistry. As far I as know, no one makes trays for 12x20 so most people use 16x20 trays. True?
I suppose I have to balance the savings with the fact that I am used to inspection developing. I don't think tubes will allow for that. Right?
Thanks,
sanking said:First, developing film in trays that just fit the film size is a recipe for uneven development. What happens is that as you agitate by rocking the tray, the developer hits the side of the trays, and rebounds at a faster speed, which gives uneven, i.e. higher density, on the edges of the film. This is a very common artifact of this kind of development. If you plan to use trays for 12X20 film, you will get more even development by oversize trays, say 20X24. Don't even consider developing your film in trays that just barely accommodate the film.
For rotary processing , you will need about 1000 ml per sheet of 12X20 film if you develop in tubes or drums. I have developed a lot of 12X20 film in Beseler 12X20 drums (of the type used for making color prints), with very even development.
What I now recommend, thanks to the experimental work and information from folks like Clay Harmon and Michael Mutmansky, is that you use a slightly higher ratio of Stock A solution to Stock B solution for rotary processing. Say, instead of 1:1:100 use 1.5:1:100 or instead of 2:2:100 try 3:2:100. The greater amount of Stock A will minimize the development of general stain, or B+F.
Sandy
jdef said:When I develop 8x10 negs in 8x10 trays, I use brush development and have never had a problem with uneven development or added edge density. To know for sure, you'll have to sacrifice a sheet of film, flash it to an average density, and develop by whatever method you want to test. If your process causes uneven development, it will show up in your test neg and save you from ruining an important one. I know the idea of sacrificing a 12x20 negative might be hard to swallow, but the idea of losing a 12x20 image to a flawed process is a nightmare. Best wishes and enjoy your big negatives.
Jay
colivet said:Sandy, what you say makes a lot of sense but I have already 2 trays that I have made to 14"x24". I thought that would be enough space around the negs to avoid weird behaviors. From what you say it is not.
I really want to keep things simple and the idea of brush developing mentioned by Jorge appeals to me. I heard that brush development is the best way to go for even negatives (without resorting to motorized processing) and I would think that using a brush with the already made trays would be fine but if need be, I will buy trays or make them myself out of fiberglass.
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