Active vs. Passive 3D glasses

Planar 3D Monitors utilize passive 3D glasses whereas the Avatar 3D movie experience depends on active shutter glasses. What does that mean? Went to see the Avatar 3D finally and got this question from my friend. So, here's the explanation:

The structure of the glasses is different. The passive glasses are polarized. Planar’s glasses have linear polarization, which is different in each lens by 90 degrees, for example, so that one lens has horizontal and the other vertical polarization. In the case of Planar’s 3D monitors, the StereoMirror technology is utilized to show two different pictures from two different displays so, that each eye gets a different image – simultaneously. Difference here compared to the Avatar 3D experience with the active glasses is, that there is no flicker: in Avatar your eyes are basically getting an image alternating in left- and right-eye. This can give a slight feeling of dizziness and the view seems darker as one eye only sees at any one time. When going to see Avatar 3D, I noticed slight feeling of disorientation during the commercials but it vanished after the eyes adjusted to the shutter glasses.

One main difference is, that active shutter glasses require power of some sort, whereas passive glasses don’t. This adds to the design: active shutter glasses look bulky whereas passive glasses can be light almost like the smallest of sunglasses. This is why they also easily ”vanish” at exhibitions where we’ve demoed the Planar 3D monitors: people mistake them for sunglasses. Well, now you know: they are not (so please return them, when you next see us at the show!).

The most memorable difference for me as the user - at least in the case of Planar’s passive 3D glasses versus active or so-called shutter glasses used to view the 3D version of the film Avatar - was the pain on the nose! Yes, for me at least, the active 3D glasses proved heavy and hard on the nose. Had to sit with my index finger stuck between the glasses and my nose for some part of the film... The passive glasses are nice and light in comparison!

Oh, and have a look at the latest in 3D displays: Flyfire - no need for the glasses NOR the display itself! Wonder when they start making movies with THIS solution...?