I'd like to thank you! It has been quite a while since someone shed some additional light on the issue of graininess and Rodinal. The phenmenon of microreticulation is something I stumbled upon when viewing at developed film through a microscope. I provides a strange looking, additional plane of focus and may also be visible in a grain focusser.
The influence of the temperature came up some years ago in german forums. Agfa in their Textbook from 1937 - "Das Agfa Laborhandbuch" - recommended a lower temperature for Rodinal (16 C) than for their other developers (18 C, standard room temperature of the time). Several photographers tried this and got very fine grain with Rodinal and films where this previously seemed impossible, e.g. HP5+.
As I take it from what you wrote above, back in the day emulsions were less hardened and swelling may have been more of a problem with a high-pH, therfore, Agfa recommended a low temperature. With modern emulsions choosing a lower process-temperature may prevent micro-reticulation, when temperature control within 1 C can not be guaranteed. And I think under most circumstances it will be a stretch without dedicated precautions taken.
Last edited by skahde; 11-09-2011 at 07:12 AM. Click to view previous post history.