The OP's question is about the resolution of photo paper versus film, not contrast and how to control it. I did some reading on this a while back and concluded nothing useful. The resolution specs (in lp/mm) are readily available from manufacturers for film, but not so much for paper. And even so, those specs seem to be hotly debated. What information I did find suggested that the resolving power between the two are comparable, but that other factors come into play (like the texture of the paper). In practice, I don't know that it matters much. Paper should produce sufficient detail.