In non staining developers like Rodinal EI 50 really is overexposing and underdeveloping for this film.
Originally Posted by dr bob
To give a further indication of the EI of Efke PL 100 based upon my work with Pyrocat, I have found that for the density ranges that I require for Azo the film will properly expose at EI 100. For the density ranges that I would use for silver enlarging I rate the film at EI 80. Again this is with Pyrocat and minimal agitation.
The choice of developer will have some bearing on the EI. For instance ABC Pyro will not give the same speed as Pyrocat. Also the degree of expansion or contraction will also affect the EI.
I have no experience with Rodinal.
I have no experience with Efke PL 100, but I use Efke R100 (roll film in 120 format) and KB100 (35mm). I've also tried R50 and R25.
I expose R100 at EI 100, and develop in Rodinal 1+50 at 20 deg. Celsius, for 10:30 to 11:00 minutes, depending on lighting conditions (shorter time for contrasty scenes, longer time for "drab" lighting). The contrast also depends on agitation: I use 30 sec. agitation for the first half minute, and then 1 inversion and about 10 sec. agitation every minute after that.
For R50, my dev. time in Rodinal 1+50 is about 9 minutes, and for R25 about 7 minutes. Everything is shot at nominal EI - i.e. R100 at EI 100, R50 at EI 50, and R25 at EI 25.
The "Plane" shot in my gallery was done on R25, developed in Rodinal 1+50, at 6:30 minutes - in Jobo CPE 2 processor, which is the reason for shorter dev. time. Hand tank would have been 7 minutes. Shot at EI 25.
PS: presoak is obligatory! 5 minutes in Jobo processor, or 1-2 minutes in hand tank. The water comes out deep blue (or something like that, I'm relatively colour-blind )