Quote Originally Posted by Stephen Benskin View Post
You'd think that something that has been around for over 70 years would have been better defined by now. In sensitometry, 0.30 is always a stop.
Agreed.

Quote Originally Posted by Stephen Benskin View Post
With Zones, I see it as a change from one Zone to the next with the original subject is one stop. There has to be a unit of measurement or else it's just gibberish.
Not agreed. Well not agreed that there needs to be a global standard.

The zone system is an artistic ruler.

Zones were specifically designed to translate various and sundry personally defined (artistically chosen) SBRs into a single chosen target paper's range.

We each define how much of a given scene is important. Whatever that SBR is gets hacked up into the zones. The zones may be 1-stop or 0.7 stops wide or 1.2 stops or whatever.