(CNN) Long before product placement became commonplace, cars, watches, pens, cameras, soft drinks and other identifiable items were chosen as props per their suitability for the role. Think of James Stewart's Exakta VX camera with extra-long lens in "Rear Window" -- ideal for a professional photographer, especially one spying on a neighbor from a great distance -- or the banks of open-reel tape decks used by Gene Hackman in "The Conversation." Nowadays, the closing credits after a film are required to state that product placement was practiced. Blunders, alas, occur, and websites are devoted to anachronisms on screen. For every fastidious prop master, such as the one who ensured the veracity of "Mad Men," there are others who failed to realize that quartz watches didn't exist in 1941.

Source: CNN March 27, 2017 09:45 UTC