In broad terms, digital really out performs film in rendering high acutance images. In theory, pixels side by side, could make abrupt changes in contrast. However film, with its layers of silver halide crystals, can never render the same degree of edge sharpness. (Mark Cassino)

The acutance is the geometric mean of the slope of the edge trace divided by the overall density difference. Acutance in a photographic emulsion depends to a large extent on the nature of the developer used. (Net Industries and its Licensors)

One often quoted property of Rodinal is that it increases the grain of the film, that isn't true. At the 1:25 dilution the developer will give you very similar results to any general purpose developer in both apparent grain and acutance, higher dilutions will show progessively more grain along with increased accutance. (Mark Antony Smith)