Time for Efke R25 in Rodinal

I already found some information searching the forum, but this
particular combination wasn`t mentioned.
Has anybody of you experiences with the Efke R25 in Rodinal 1+50? It
would cut down the testing range (not really making testing
unnecessary).
The goal should be a pronounced (sharp, not necessarily large) grain
with a medium to low gamma (negs in ID11 became still really hard
printing on grade 0). Shooting 6x6 and 6x9 the loss in finegrain is
rather wanted. I expect the emulsion still to have a finer grain then
the R100.

 

Try Rodinal (1:100) for 9 minutes at 68 degrees.

 

For 1+50, their sheet indicates 4.5 minutes at 68F. Prewet 1 minute in water, agitate 30 sec then every 15 sec. (1+25 is 5 min).

 

Did you look at the Massive Dev Chart at Digital Truth?

 

http://jandcphotography.com/developing_times.htm