Some observations about 3D

[Gavin Greenwalt]

BTW for anyone who has used a VR headset with head tracking it's an amazing thing when the parallax tracks. Even if it's subtle. The immersion is pretty incredible.

Even in 2D the effect is pretty amazing.

 

[Hrvoje Simic]

With a huge image like that of an Imax screen combined with a wide screen production my eyes tend to "meander" around the frame to pick up stuff in the background or foreground, some place where the focal plane might not be at that particular moment. Then the eye tries to compensate with its lenses; and they try hard because the focus doesn't change no matter how hard they try. And THAT gives me headaches.

I've explained the same issue to my friends before Avatar so they'd be prepared for that. The price of immersive entertainment is limitation in "watching around the frame" in higher convergence shots.

Indeed, a landscape doesn't move much as we move out heads, but if we're viewing the landscape framed by the branches of a nearby tree, we should see the proper parallax shift as we move out heads. We're constantly moving our heads, and because stereo doesn't react right, it's less real

As Gavin mentioned it, head tracking is the key for that and it works great.

http://www.youtube.com/watch?v=Jd3-eiid-Uw

Once/if Nvidia Vision glasses incorporate this feature, we will be able to get more real effect, one step up.
The price of that is one screen, one real time CGI engine and two virtual cameras per viewer, currently possible only in computer gaming world.

and the single focus plane is said to be the cause of eye strain in stereo viewing.
Graeme

With experience in 3D entertainment and faster adaptation to the focus plane this particular problem practically goes away (speaking from personal experience), being a factor which viewer can control. There are other, more important issues IMO, which viewer can't control and affect eye strain - type of editing, shooting style, inappropriate DOF, missed convergence, picture resolution and temporal resolution, etc...

 

[Gavin Greenwalt]

One way in a personal setting that focus could be corrected for is to use eye tracking and then focus the picture on that point. Again requires real-time processing but we're only a decade or so away from that.