Jeff Liebermann wrote:
On Mon, 15 Feb 2010 22:44:13 -0800, Richard Clark
wrote:

Without having gone
further into researching it, I have a hunch that I am encountering
circular polarization here.

Yep. RealD XL 3D is circularly polarized:
http://en.wikipedia.org/wiki/RealD_Cinema
http://en.wikipedia.org/wiki/List_of_RealD_films

"How to avoid getting a 3D headache while watching Avatar"
http://www.shadowlocked.com/index.php?option=com_content&view=article&id=70:ho w-to-avoid-getting-a-3d-headache-while-watching-avatar&catid=41:feature





Which makes perfect sense, since it means that if you tilt your head,
you don't swap images between left and right eyes. A very clever use of CP.