Because so many people have expressed an appreciation for Fuji's Neopan Acros 100, I have been working with that emulsion on and off for 2 years, mainly in my pinhole cameras - if for no other reason than its ridiculously pinhole-friendly reciprocity. However, I have found that I almost always have problems with "pock marks" (conspicuous dark round spots with lighter outer rings) on the negatives that appear ONLY on this film (I use several Ilford and Kodak emulsions as well).
See:
(This is one corner of a 6 X 18cm neg, and this area represents approximately a 2X2cm area)
Process:
I develop all my own film, and I have used Neopan Acros in combination with Rodinal and D76 in various dilutions. I used Rodinal exclusively for the first year or so and thought perhaps it was causing these dark spots with lighter rings (I hope they are easily identified in the image - click to see full size, please), but they appear when using D76 as well. (The above negative is processed in D76, by the way.)
I have been using a presoak for 1-2 minutes with all my films and I measure temperature carefully. All chemistry is maintained within 1-2 degrees F at all times. I have been using an indicator stop bath, but I experimented by using two water rinses instead, but that change had no effect. I have used a rapid fix and I have used a hardening fix - the marks show up either way. I do a rinse after fixing and then a 2 minute Kodak Hypo Clear bath before a final wash. Oh, and I always use mineral-free (reverse osmosis) water for my chemistry.
So, I have to wonder - is this just a defect of the emulsion, or what? Does anyone know why I am getting these marks, and what I might do to prevent them? Thank you.
Paul
See:
(This is one corner of a 6 X 18cm neg, and this area represents approximately a 2X2cm area)
Process:
I develop all my own film, and I have used Neopan Acros in combination with Rodinal and D76 in various dilutions. I used Rodinal exclusively for the first year or so and thought perhaps it was causing these dark spots with lighter rings (I hope they are easily identified in the image - click to see full size, please), but they appear when using D76 as well. (The above negative is processed in D76, by the way.)
I have been using a presoak for 1-2 minutes with all my films and I measure temperature carefully. All chemistry is maintained within 1-2 degrees F at all times. I have been using an indicator stop bath, but I experimented by using two water rinses instead, but that change had no effect. I have used a rapid fix and I have used a hardening fix - the marks show up either way. I do a rinse after fixing and then a 2 minute Kodak Hypo Clear bath before a final wash. Oh, and I always use mineral-free (reverse osmosis) water for my chemistry.
So, I have to wonder - is this just a defect of the emulsion, or what? Does anyone know why I am getting these marks, and what I might do to prevent them? Thank you.
Paul

