I remember a story Clint Eastwood told me years ago, after he made “The Eiger Sanction” (1975). There’s a scene in the movie where Clint’s character dangles in mid-air at the end of a cable hanging from a mountain. He’s thousands of feet up. Clint, who also directed, did the scene himself.

“I didn’t want to use a stunt man,” he said, “because I wanted to use a telephoto lens and zoom in slowly all the way to my face — so you could see it was really me. I put on a little disguise and slipped into a sneak preview of the film to see how people liked it. When I was hanging up there in the air, the woman in front of me said to her friend, ‘Gee, I wonder how they did that?’ and her friend said, ‘Special effects.’”