I never knew that the Efke KB/R 100 film was so versatile and forgiving. Recently I travelled from the US to Sweden to see my family, and especially the new family member - my nephew..
I desparately wanted to photograph him, and had been using Ilford HP-5 all day in my MF setup. Now that we were indoors, I judged by the light in there that 1/125 @ f/4 or f/5.6-8 by a window would be sufficient. So I was firing away, thinking I had HP-5 in the camera. When I change rolls I realize I had an Efke KB100 in there and figured I was screwed...
One cannot give up however, so I went back through my notes and guesstimated by using data from normally developed rolls, that Rodinal 1+50 @ 68*F for 20min ought to do the trick. To keep contrast down some, I agitated only for 5sec every minute instead of my normal 10sec.
To my vast surprise the negs turned out absolutely beautiful with a full range of tones and good contrast overall. Best push processing I've ever achieved.
Just thought I'd share my joy and info, as somebody perhaps could find it useful in case they had a brain fart like mine...
Saint Paul, Minnesota