Sydney Pollack

With a movie you're creating from the beginning this particular work, let's not call it work of art, because very few movies are works of art, let's just call them bits of popular culture, whatever they are, sometimes very rarely by accident a movie becomes a work of art.

The historical novelist has to consider what has actually happened, while the SF writer is dealing in possibilities, but they are both in the business of imagining a world unlike our own and yet connected to it.