The difference is usually plain, and if not, it is visible on close inspection. Even if digital artifacts do not easily give it away, tonality does (as do obvious things like manipulation of certain levels or types). I would say this about anything but the very highest quality prints from digital films made by people who really know what they are doing. With pictures shot in ambient light, the difference is plain as day to me. It is harder for me to tell when the shooter has used controlled lighting, as good lighters simply tailor their light to match the medium being used. I have never once seen a digitally-captured print that just looks like a plain photo, as opposed to like a digital photo, by a photographer who did not really learn their craft with film.