That makes perfect sense. Thankyou. I now understand what Bill was trying to tell me. And by metering different parts of the test neg, I can get an idea of the ranges in play too, which should teach me more about judging the densities of any given neg - which I am still having trouble with. I will give it a try. And I guess I need to do it again with different papers and film stock combinations.
Mystery solved. Thanks to all.