It's a bit more complex. IMAX 3D technology uses plane-polarized light. Indeed, last night, when I tilted my head, the image darkened some – a sure sign of plane polarization! RealD uses circular polarization, but IMAX 3D isn't RealD. I might go see the film again in non-IMAX 3D at a venue that I believe is using RealD, if only to compare the two.