Director Alejandro González Iñárritu’s Birdman deserves the high praise it has received from critics, and not just for its brilliant writing; hyper-meta deconstruction of fame and self-perception; and excellent acting by its stars. Famously, Birdman was filmed to look like one continuous shot.

To make this work, the director and cinematographers had to get really creative, utilizing tricks like time lapse and dark spaces for cuts between scenes. But the film doesn’t rely entirely on movie magic: parts of the movie are truly composed of massively long takes. In this behind-the-scenes clip, leading actor Michael Keaton explains how one such scene was made.

The clip in question trails Keaton into his character’s dressing room, then out of the room, into the labyrinthine theater’s backstage, which, as Indiewire points out, grows smaller and tighter as the tension rises. Along the way he encounters several other characters before bursting out the front doors, allowing the editors to add in a seamless transition to the next scene.

Incredibly, all of these shots were done with hand held cameras, with Keaton describing one cameraman who was constantly drenched in sweat from the effort of filming in this style. Their work paid off: Birdman‘s energy is propulsive, and keeps viewers glued to the screen till the gorgeous ending. No spoilers.

[via Indiewire]