I've been printing PanF (35mm) for a few months now, with limited success. (I'm a newbie, so I'll take what I get. Just producing discernable images is half the battle for me.) But I recently attempted to print a frame from a roll of TMax and found that I wasn't developing anything on my test strips. My usual timing for test strip exposure is about 7 seconds per, until I get close to what I'm looking for. With my lens stopped to f11 or 16, I usually see print times in the 18-35 second range. So, I kept increasing times to a max of about 65 seconds! I finally got an image to develop... What gives? If I remember correctly, the Tmax is ISO400 and the PanF is 50. Is it differences in films, emulsions, layers, densities...or, (what I really think it is) am I messing something up???