Julian Schnabel has directed four films, of which I have seen three: Basquiat, Before Night Falls, and The Diving Bell and the Butterfly. All three are quite good, and not of a kind I would say. They are all quite unlike his prior work -- his paintings, etc. It is a curious case where the second line of work - the film making -- is much better and more interesting than what brought Schnabel fame in the first place. The latter I found to be entertaining, but only. Post-card art I would say. The movies are visually interesting and inventive, well-paced, intellectually engaging. Thoughtful. The other art is commodity work.
Basquiat, for example, conveys the art effectively, and also the person. It is a good biographical film, at least in the sense that it conveys a good deal about the nature of the artist, his context (what the old would call his milieu), and the drift into death. It is one of the best about a visual artist that I have seen. (There is a video about Cartier-Bresson that is quite good as well, although that is almost all art.)