Quote Originally Posted by Michael R 1974 View Post
I don't know where/if anyone called it a universal speed point. As you know it is simply a common targetted net negative density called "Zone I" in most Zone System books/methods, used to determine a working EI that presmubaly will lead to "full" local contrast around the "Zone III" density.
But how legitimate is that? You are referring to a system/method and what it states. Does the theory support the premise and if so where is it? And the reason I used universal is that it is the speed point only in a specific situation and cannot be applied to all situations.

One of the questions I propose is what is film speed. And one of the conclusions is that there is a difference between film speed and exposure. This is a distinction not frequently made.