When there’s a scene that’s meant to evoke physical hugeness (say, a establishing shot of a spaceship battle of massive ships), movies do 3D. But they should NOT, cause parallax immediately informs of smallness, and so all the elements feel tiny, achieving the exact opposite of what’s intended.
Then, when jumping to the actual close/over-the-shoulder dialog shot, the 3D is gone for some reason. However, that’s when you need it the most, when parallax and proximity matters, when you want to create a sense of intimacy (within reasonable margins to prevent discomfort to the audience)
Of course, it all boils down to the fact that the 3D department works on their own separated from production, and also to technical reasons. For example, spaceships are CG, and therefore 3D at source, so getting a depth-image from the composition team is easy. So the 3D department (which doesn’t talk to the 2D cinematographer) adds 3D effect to that shot (breaking its intent) and goes home thinking they did a great job. Meanwhile, live action footage (characters closeup) doesn’t come from the CG department, and so it comes without depth information. Therefore doing stereo/3D is more difficult and usually avoided, despite those shots are, if anywhere, where the 3D should be applied.
Another technical mistake is that the film industry still hasn’t learn to apply 3D in physical units (meters or inches) not in “pixels”. If they did so, the 3D/stereo effect would adjust automatically to each shot without much art direction needed (besides tweaks).
As a result, in today’s films grandiosity gets caricatured by 3D, and opportunities for intimacy wasted. They should learn 3D is not a popcorn selling feature meant to put a spaceship in your face, but a tool of the medium, like lighting of focal length or composition, and they should use it accordingly.
And it’s being 7 years since 3D arrived to our cinemas. You’d think they’d have learnt by now.