In the 1970s and 80s, though, LEDs were routinely dismissed as ineffective. “There’s no way that this little dinky toy light is going to do anything useful – that was the attitude at the time,” says Paul Scheidt, senior product marketing manager at Cree LED, a major manufacturer of the devices. These expensive and weakly emitting light sources were fine for a tiny red indicator light or an infrared TV remote, maybe, but little else.