Quote Originally Posted by Michael R 1974 View Post
Andrew, I've been working on this for a while. To start you might want to refer to some of the work Howard Bond did on this:

http://phototechmag.com/black-and-wh...y-howard-bond/
Thanks for the pointer to this very interesting article.

I see he also targets Zone III and his curve lies roughly between my Zone III and Zone V curves although he gets a somewhat smaller correction (around 0.25 stops per stop of measured exposure).