I'm a bit late on this discussion but I get about 46-48 rolls of film on average when using AF, though for some reason it drops to about 40 if I switch a lot between macro and standard modes. I always used to carry a P-8 Power pack with me but now, since I am always shooting with my Contax 645, I have also bought the P-8D and get up to 60 rolls when using it. The combination of the AX, D-8 back and a power pack is superb, though not exactly something you can put inside your pocket!