One evening last October, Apple’s tight-knit team of designers took their seats in San Francisco’s Castro cinema, excited to watch the premiere of a new documentary about their hero Dieter Rams.

The legendary former head of design at German electronics manufacturer Braun, Mr Rams’ simple and elegant line of appliances, clocks and record players embodied his maxim of “less, but better”. His influence has been felt keenly by Apple design chief Jony Ive, who has brought that ethos to his iPods, iPhones and dozens more Apple products over the past 20 years.

But as the film played, it turned out Mr Rams was uncomfortable with some parts of that legacy. Gary Hustwit’s documentary shows him standing in a bustling Apple Store, lamenting that people spend more time looking at their iPhone screens than each other, and deeply concerned about the environmental impact of all the gadgetry that surrounds him.