The last 20 minutes 'or so' of the next Harry Potter are to be presented in 3D when you watch the film in IMAX cinemas.
This is a terrible idea. It reduces any sense of immersion the audience might be experiencing to suddenly derail the flow and turn the climax of the film into a rollercoaster ride. "Hang on, it's just getting going, racing towards the big finish... and it's time to put your glasses on!"
Warners did a similar thing with Superman Returns and that was equally silly of them. Don't they want use to lose ourselves in the film? No - they just want to lure us in to the premium priced screenings, barking at us like half-baked Barnums.
What's more, as the Potter film wasn't shot in 3D but is being converted the effect will be even less welcome. Live action conversion from 2D to 3D means that the effect will be rather limited in most shots, with the characters, sets, scenery and so on looking less like rounded, solid objects in space than a series of flat planes, not entirely dissimilar to a cardboard cut-out puppet theatre.
The whole film should have been shot in 3D to begin with. So should most films be, frankly. And one day soon, they will be.