Watching 3D without those annoying 3D glasses is the holy grail of 3DTV. Unfortunately, we’re a long way from glasses-free 3D in home theater applications.

You’ve probably read exciting stories about this technology, and researchers are definitely working on it. But the concepts shown so far have serious limitations. They often require that you keep your head in a fixed position, or perhaps one of several fixed positions, between which the 3D image reverts to an unwatchable 2D picture. One demonstrated concept allows you to move around as a camera tracks your location and adjusts the image accordingly to maintain the 3D image, but this isn’t exactly the ticket for a family 3D movie night.

You’re likely to see glasses-free 3D first in computers, where a single viewer sits in a near-fixed position relative to the monitor. Advertisers will also find it attractive. But for home video, we suspect that effective, glasses-free 3D is years away.