Bong: Just so there's no misunderstanding, although what you're doing may be correct, how you're describing it is not. It's not that you are supposed to look for the negative "with a 0.1 density (Zone I)". Instead, you're looking for the exposure that will produce a .08 to .12 density OVER FILM BASE PLUS FOG! Your description would not work with many films because their base density and fog is ABOVE 0.1. Assuming you did it correctly, despite your description, then that might indeed be your film speed WITH YOUR CAMERA, METER, DEVELOPER and PROCEDURE. All you are looking for is consistency, not a specific number. Just what is right for you.(posted 8500 days ago)Have you proceeded with the next step: determining your correct negative development time? Believe me, the two are NOT necessarily the same. Rather than fill this with the details, I suggest you find a copy of Fred Picker's "Zone VI Workshop" which provides the instructions. Normally the first test should reasonably define your film speed, but occasionally, it might be off a bit. The proper development time will produce a negative that, when exposed for Zone VIII at the tested ASA rating, achieves a density that will produce a print value of VIII on YOUR printing paper. It's not easy. But when you find it, you've got it - forever! Then you can get on with what's important - taking real pictures. Good luck.