Perhaps you think you’ve never heard of Ken Burns. But if you’ve ever been to a wedding, say, and watched a montage of photographs where the camera seems to pan in and around the still images, creating the illusion of movement, you’re watching what’s called “the Ken Burns effect”. And in every Apple computer for the past decade you’ll find the effect available in iMovie. “It’s saved countless millions of bar mitzvahs, vacations and weddings from descending into boredom,” Burns laughs as we talk on the phone. He’s in Boston and has agreed to speak to me at 6.30am — his time — so busy are this film-maker’s days. He says he knows what he’s doing pretty much every day up to 2019.