Gary Miller (gmphotos@earthlink.net)
Sun, 06 Jun 1999 15:31:04 -0700
Michael;
How did you arrive at the 9 min developing time in the Jobo tank. This may
not be the ideal one for your 5x7 film situation. One trick that Richard
Sullivan and Carl Weese told me was to check my pyro processed negatives for
contrast by contact printing them onto variable contrast silver paper using
no filters in the enlarger. If this print looks normal then the Pt/Pd print
should be very close to right on. As far as the levels of stain to silver
in the pyro negative someone else with more pyro experience will have to
respond. But this is just a thought to get you started on solving your
problems. I have been developing my Bergger 200 8x10 sheets in Rollo pyro
in a Jobo Expert drum on a Beseler motor base for 9 mins at 70F. This 9 min
time includes filling time. My protocol for processing is very similar to
the one that you are using. I have also found that you do not need to
reverse the processing tank end to end, east to west as Carl calls it, to
get even random developing patterns. I have noticed that the Beseler base
is far from perfect in its alignment and the way that it rotates so that a
wobble is introduced into the system. I have also found no difference if I
periodically run the agitation in reversing, then in one direction
constantly, and then switch back to the alternating directions. So I just
let my tank run in alternating direction without touching the system for the
entire process. Good luck.
GM
This archive was generated by hypermail 2.0b3 on Thu Oct 28 1999 - 21:39:36