"Barack Obama's amazingly consistent smile."

Barack Obama's amazingly consistent smile from Eric Spiegelman on Vimeo.

Via Glenn Reynolds, who admits he does the same thing.

People who pose for a lot of pictures — successfully — develop a natural-looking, reflexive smile. Don't mock it. It's very useful. I went through most of my life feeling awkward doing photographs as if it was phony to smile when it wasn't backed up by genuine happiness or amusement. You don't have time to summon up real feeling or its simulacrum. You're not filming an Oscar performance. Just do that winning, automatic smile for the camera and save your worries about real human feeling for less artificial encounters.