hka said:
Sanders,
I was not lucky with my developments in Rodinal. I tried at different dilutions from 1:25, 1:50 and 1:100 and also different speeds and develop times but still de highlights are completely blocked. Above you mentioned something like the Jobo instructions can you explaine what the are and how do you do it? Maybe it will help to understand what's going wrong by us. Thanks.
Sure. First, equipment: I process 4x5s on reels in Jobo 2500-series tanks, and 5x7s in Jobo 3005 and 3006 expert tanks. (I squeeze 10 5x7s into a 3005 tank by taping two negatives along their long edge, on the base side, and slipping them as if a single sheet into one of the 3005's 5 cylinders. You have to rinse them longer outside the tank to remove the antihalation dyes under the tape but it works.) And I spin them on roller bases from Unicolor, Beseler and Chromega. So, I am not gentle with my film!
Film: Over 95 percent of my work is in TXP. But on occasion I will shoot Bergger. I expose the TXP at EI 160, and the Bergger at EI 80. Typically, I'll proccess the TXP in a 1:50 Rodinal solution for 12 minutes, and reduce the time for Bergger by about a minute.
Process: Jobo recommends that you prerinse the negatives for five minutes before developing. Jobo thinks that the water soaks the emulsion and slows and evens out the development. I like it because it washes off the antihalation dyes. (Except under the tape on those 5x7s in the 3005 tank.) Jobo advises that, if you prerinse, you should start with your usual b+w development recipe, without adjustment.
I prerinse and stop with tap water. Developer and fixer get mixed with tap water. I reuse the fixer until it exhausts. Final rinse is out of the tanks -- the 4x5 reels go into the sink, and the 5x7 sheets get washed loose in my print washer.
It works for me. The results are indistinguishable from what I get using minimal agitation in the Combi-Plan tank.
Another poster talked about the problems of exhausting out Rodinal at high dilutions with the small volume of developer used in the tanks. That might be a problem, but it is not a problem induced by the mechanics of constant agitation.
Over the years I've come to conclude that a lot of the advice floating around on processing film is voodoo. You can't see inside the developing tank. You pull out the negatives one day and something's gone wrong. You take a guess. It's probably wrong. But you come up with a solution to the problem you've imagined, and pass it around, and soon enough it passes as Truth. Enough already.
As I said at the beginning, I am not an expert at this. And I remain open to the possibility that my experience is not representative, and that others have seen real differences in their own darkrooms. But in all the years I've seen people opine on this topic, I've yet to see anybody offer any examples of the supposed benefits of intermittent agitation of negatives in Rodinal.
Please, if I am mistaken, educate me.
Sanders McNew
www.mcnew.net/portraits