Quote Originally Posted by Michael R 1974 View Post
Bill, I think there are a few reasons. See me latest post in the ISO thread. This is what I ultimately wanted to get at in that thread.
Ah, but you touched on one of about 30 topics that I am anxious to figure out... I'll keep following your thread and add where I can...

For cross-reference...

Post 72 of this thread...

ISO Speed Determination Constants