From the Wikipedia article, of the 13 depth cues, only 2 aren't properly present in 3D films - accommodation (having to focus the eyes) and peripheral vision - and the peripheral vision cue is also missing from regular cinema, TV etc.
So are there more things going on here? It seems unlikely to me that the focus of the eye lens is having a big impact.
I don't know about the accommodation, but isn't the loss of peripheral vision like looking out of a window? Think of the movie screen as a big window into the world.
Not on the list (I think) but what about head movement of the viewer? If I move my head slightly to one side the picture stays the same while I expect to look behind an object.
Accommodation makes a big difference if you're near- or far-sighted.
Re:Keep doing that and you'll go blind
by pavel_lishin on Thursday February 11, 2010 @10:13AM
(#1117742)
Most of the cues listed seem like they are still used in a 3D film - aerial perspective, relative size, occlusion, etc can be stimulated and peripheral vision is irrelevant.
The Wikipedia entry on depth perception (an excellent read) lists ten different cues that your brain uses to figure out exactly how far away something is. Parallax is just one of them. Since the various movie and television display technologies only offer parallax-based depth cues, your brain basically has to ignore several other cues while you're immersed in the world of Avatar. This is why the 3D of films doesn't feel quite right.
I agree that 3D films often feel a bit weird, but I'm not 100% sold on his idea of why this should be. The Wikipedia article names many visual cues that are present in 3D movies as well (e.g. relative size, perspective, texture & lighting etc.). It seems conceivable that your brain is "tricked" and has to adapt to the new situation, I just don't know if his reasoning is valid.