The F4 meters very well, with just about anything except with a banana or an inner tube. Seriously, it's got an extra meter to show the amount of stops you should correct it with... I think I missed it out on one stop here & there, but the tube shots were just 1/4th of the roll. So the darkness didn't just happen to the macro shots only. Velvia doesn't punish you as hard I guess, or do you recon 100 is better in average situations than 64 ?