My order of Spur Acurol-N arrived. It took about 3 weeks. I'm shooting 11x14 Bergger Pancro 400 at ASA 200. The developer comes with literature that recommends dilution of 1+35 and developing time of 13 minutes with "inversion" (agitation) twice each minute with a resultant "soft" contrast. They say contrast can be increased by either increasing agitation of lengthening the development time. For sheet film, an inversion apparently consists of lifting the film out of the tank, tilting to one side, returning to the tank, then repeating, tilting to the other side. For sheet film, each agitation consists of 3 inversions (so, 6 per minute). In practice it took me 20 sec or longer to complete one agitation cycle, so 2 cycles meant essentially, continuous agitation. I decided to drop to one cycle per minute and increase development time a bit to compensate for less agitation. When you shoot at lower ASA the required development time or developer concentration drops somewhat. I have read that people who shoot at ASA 200 use dilution 1+50 for 13 minutes. I appreciated the YouTube video, "Bergger Pancro 400 - The Ultimate Film Review" by Analog insights. I was a little concerned about "soft" contrast. My developing tank holds 10 liters, the developer comes in 250ml bottles. So I mixed the contents of 1 bottle into my tank for approx. 1+40 dilution and developed for 16 minutes. In retrospect, 1+50 for 13 minutes would probably be fine. I shot some portraits indoors using flash, not the typical use of Spur Acurol-N, which is recommended for high resolution, detail work. I was intrigued by the "high acutance". I very much like the results. The negatives appear to have correct density and the resulting prints are beautiful. I intend to shoot more and try some extended development time at higher dilution. Jules Bobach at Analog Insights cautioned that for large format use, Spur Acurol-N stand development might result in uneven development and bromide drag. I'll let you know what happens.
I couldn't find info on the capacity of Spur Acurol-N. For my first try I decided to process 6 11x14 sheets, 2 at a time. That worked out fine. I suspect the capacity is considerably higher. As I started my last pair of sheets, I apparently lost concentration and put the sheets in the tank with photo-flo instead of the presoak tank. When I realized my error I rinsed the film and continued. This time instead of putting the film in the developer, I put it in the tank with stop. I assumed the film was ruined but I rinsed it off and developed it. To my surprise the negatives looked fine, perhaps a little less dense than the others.
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