So is it a bit like calibrating film in your camera only taking it a step further and including developing time as well?
Also thank you for the response. We were taught a b&w course, but 6 weeks is just not enough time to learn all there is to know. I don't recall my first professor mentioning this at all, however I do now remember my second professor performing this test for us, however I guess since I didn't recall it until now I didn't pick up on it well enough (tues, night class 3hrs long seemed to last forever) He will be teaching it again so I will ask for a refresher. Thanks again.