This is another tricky one. Avid researchers into such matters have scrutinised films frame by frame. Was it hair or was it shadow? Not that it matters all that much, but some people find it nice to know the truth.

Some connoisseurs opt for "Blow Up": there is a sexy scene in which David Hemmings romps with a couple of naked teenagers. The Catholic Office gave "Blow-Up" a Condemned rating.