> about 32 and 80!(posted 8264 days ago)Yep, that's about right; for most developers I've tried with it I get EI 64.
As for the ISO rating, it used to be that a specific developer and development process was spelled out to be used for ISO rating but the problem was that it was pretty useless for pictorial use because using that process gave very high contrast (and commensurate higher "speed").
That's been changed and manufacturers can use whatever they want...as long as somewhere or other thay specify what and how. Plus it's not a given they're using the classic .10DU.
Why is it done this way? Marketing. You bought "Acros 100" while you wouldn't consider "Acros 50," right?