The light on their faces: Mal is cragged, often shadowed, but strong, sad-eyed and kind. Kaylee is round, warm, and open. Sexuality and honesty. River is planed, underlit, eyes hooded. She’s a question. Simon works in angles as well, coolly handsome and hard to connect with - but ultimately he’s a romantic. Jayne doesn’t give a good goddamn how he’s lit. Zoe glows. She cannot help it. Wash is light, playful - often amongst his screens or slightly blown out by the sun of high atmosphere… Inara’s light is complex, like Mal’s. Hiding and beckoning.
-Joss Whedon (Serenity: The Official Visual Companion)