So currently in my JOBO CPP2 I am running Diafine full strength Part A and full strength Part B for 5 minutes for all BW films at rotation setting “F” which is around 40 rpm. After part B I increase the rotation to “P” which is around 80 rpm and keep it at that for the remainder of the process. My tests have shown that times around 7+ minutes in A/B can stain some films- yet 5 minutes in A/B at 75F seems about spot on to me and perfect for most scanning applications. The 1:1 development of Diafine decreases the shadow detail at higher EI… for example at 1:1 TX dies after about EI 800 whereas with the full strength process as outlined above EI 1600+ is very solid (note: box speed at 1:1 is about perfect- for box speed). With regards to streaking…. none, full strength or 1:1. An obvious advantage to full strength is that Diafine can be used over and over again for a lot of film where as the 1:1 is a one shot developer. I have personally used Diafine (1 gal A/B) full strength for well over a year without issue…. if it becomes a bit dirty just run it through a new clean coffee filter and presto! Perfect developer ready for more film.
Viva la Revolution- Stephen