20 Actors Who Quit Movies For Insane Reasons

20. He Hated The Camera Rig - Robert Downey Jr. (Gravity)

Though George Clooney ultimately played the role of astronaut Matt Kowalski in Alfonso Cuarón's Gravity, the part was originally intended for Robert Downey Jr.

But Downey ended up walking away from the film during pre-production, when he met with Cuarón to test out the camera rig being used to shoot the actors.

Due to the CGI-heavy nature of the film, the actors' performances were largely captured inside of a bespoke camera rig called a "lightbox," where thousands of LED bulbs were used to simulate outer space.

Because of the cumbersome nature of the rig, actors often had to spend hours at a time inside it, and would communicate with Cuarón through a headset.

The gravity of this all dawned on Downey when he tested the lightbox for just 20 minutes, at which point he realised that the experience would simply be too uncomfortable for him, and so he took his leave.

While every actor has their limits where comfort is concerned, it's genuinely surprising that Downey - an actor so well-versed in the laborious nature of blockbuster movie production by this point in time - was spooked by this groundbreaking shooting method.