The relationship between stage and screen has always been fraught with antagonism and suspicion. One working in two dimensions, the other in three, they don't speak the same visual language. But recent events have helped to eat away at the status quo. On the one hand, theatre has grown increasingly intrigued by the design properties of film. Flat screens have popped up all over the place, notably in Katie Mitchell’s National shows and at the more ambitious work of the ENO. Meanwhile, theatre and opera have been encouraging those who, for reasons of distance or price, can’t make it to the show itself to catch it on a cinema screen instead.