Originally Posted by Francesco
You ask a valid question. I will do my utmost to provide what I think to be true to answer your question.
According to the tests that I did on Azo paper which have been verified by my experience in exposing and printing film to the density range that the paper will support, the paper really does not care what the general density of the negative is. I would offer this example to illustrate the invalidity of the general density argument. If we had a scene in which there were three zones of luminance and we exposed the lowest zone at a Zone V placement and gave normal development, we would find that our negative would exhibit an overall dense appearance but it would lack density range (contrast). This negative certainly would take longer to print but the print would appear flat. We would have a print that exhibit tonal values of I to IV or we could also print it to exhibit V to VIII The only effect of this increased overall density would be longer printing times.
The paper does have the ability to represent a given density range. If the negative is exposed so that the shadow densities are placed higher (off the toe of the film curve) then better print shadow tonal separation occurs. However if that is the case and the negative is developed to the density range for the full potential of Azo paper then the highlights will go onto the shoulder of the film with most films.
I could imagine a scenario in which one placed the shadow values at a Zone IV luminance (for instance) and the low densities would be .65-.75 (for instance). The negative then would appear to be very dense if we developed the negative to a high value density of 2.05. In fact it would look to be almost bullet proof. However our density range in this case would be 1.30 to 1.40 instead of the 1.60 that the paper will hold. The negative would print easily and it may give a nice print. It would however fail to reach the potential of the paper. Either the shadow values or the highlights or both would be compromised. Certainly there may be images that can not or should not have the absolute dmax or dmin that this paper will exhibit. But there are others in which scintillating high lights or deep black shadows are important. It depends a great deal on the image, the photographer, and his vision.