Michael, I don't believe your theory about the goal of the Zone System has any merit. The EI difference is simply a remnent from before 1960. I guess you could consider that the Zone System didn't have to change with the change in the ASA standard because it was achieving it's goals. You could also consider, it was luck that there was a correlation with the ASA method because of the safety factor in the ASA standard which compensated for the Zone System not incorporating flare. Otherwise an excellent analysis.
Last edited by Stephen Benskin; 03-18-2013 at 11:33 AM. Click to view previous post history.