There's important differences in color response, although a lot of the most modern films have very similar color response to digital (because the one was design

There's important differences in color response, although a lot of the most modern films have very similar color response to digital (because the one was designed to mimic the other, obviously). The grain is also difficult to mimic precisely; film, being an analog medium, has sometimes superficially higher resolution than a lot of digital sensors but this is because it degrades continuously (whereas digital tends to be superb until you reach the handful of pixels range). This is all, of course, in the context of color films. Black and white films are particularly difficult to mimic with digital, partly due to spectrum rendition issues that are difficult to recreate in post processing, partly due to very different grain structure (B&W grain is generally sharper than the dye clouds you get with color films), and it must be admitted partly due to romanticism on the part of film partisans.