Page 1 of 1

rodinal 1:65 time for tri-x

Posted: Thu Dec 15, 2005 11:49 pm
by kcf
Jon Mided, I read your recommendation of Rodinal 1 to 65 for twenty minutes for pushing TMAX 400 to 6400. Would this also be a good dillution for tri-x to 6400, and if so, what would the time be? And then, would this dillution work also for pushing tri-x to 3200? What would the time for that be? Also, should there be limited agitation when push-processing for long periods? What does limited agitation actually mean?

Posted: Sat Dec 17, 2005 7:17 am
by Digitaltruth
No, I don't think this is a good time for pushing Tri-X. It was only a suggested approach to test with TMAX 400 based on the need to control contrast and the lack of push processing data that is available for this combination. In the case of Tri-X, the film is more suitable for push process techniques, but there is already a published time of 15 minutes at 1+60 for normal exposure. If you are going to push Tri-X to 3200, then you are going to create a contrasty neg and there is no way around this. I would recommend starting with the 1+50 dilution at 33 minutes that was submitted by another user. This seems about right to me based on my own experience, but a lot will depend on subject contrast and your method of determining exposure.

Limited agitation is a subjective way of saying not to over agitate. Different tanks, volumes, agitation methods make it difficult to be too specific and a development time is only ever a starting point until you determine what is best for the type of negs you are trying to produce. If I were developing film based on this data I would probably agitate for the first 30 seconds, and then 1-2 times per minute. Once you are half way through the development, say after about 15 minutes, I would reduce the agitation to once every 3 minutes. This might improve the developer's compensating effect and stop the highlights from being unnecessarily overdeveloped.