I have always been taught that the darker the negative, the more over exposed it is, which will result in a lighter positive, the lighter the negative the more underexposed it is hence the darker the positive, dark negative equates light positive, light negative equats dark positive, in very simple terms, if the negative is dense, it is overexpose, if the negative is light, then it is underexpose, and both situations will create the exact opposite on the positive paper.

And I know this is about as clear as mud.

Dave Parker
Ground Glass Specialties