Originally Posted by aaronwt
What about the DOlby 3D glasses? My brother gave me a pair of IMAX 3D and Real3D glasses to use last year at the theater. But then when I went to my first Dolby 3D showing, I found out that they use something completely different from what IMAX 3D and Real3D use.
The Dolby system is completely different from those other two.
IMAX 3D uses LCD shutter glasses that alternately turn black, and the image in the screen alternates between the left and right views synchronously.
RealD uses circular polarised lenses, and projects both views at the same time with opposite polarization.
The Dolby system has slightly different color filters for the red, green and blue components in each lens. The two projectors, one for each view, are using RGB primaries that match those respective deviations. The lenses then let through the primaries from one projector, and block the ones from the other projector.
So, basically, if a normal TV or projector would have the three components for red, green and blue at specific wavelengths, then the Dolby system would have one view with wavelengths a little bit shorter (higher frequency) than those, and the other view a little longer wavelengths (lower frequency). The eye then percieves the color from those deviated primaries in the same way as from the traditional three primaries. Any off-color effect from that can be compensated when authoring the pictures. Some describe it as "anaglyph on steroids".
The advantage of both RealD and Dolby against IMAX is that both views are visible at the same time (caveat: many RealD theaters use a single projector and toggle the polarity with a "Z-Screen" in front of the lens, but at a very high frequency of 144 Hz), and continuously, while IMAX might introduce flicker. The advantage of IMAX and Dolby against RealD is that they work on white screens, while RealD requires a silver screen to maintain polarization. The advantage of RealD against the other two is that the glasses are really cheap.
RealD is essentially known as "Passive" 3D on LCD and OLEDs at home, while the IMAX one is known as "Active" 3D, used on Plasma TVs, with projectors, and, puzzling, with a lot of LCDs. (LCD lends itself to passive 3D, due to the inherent polarization of the screen technology, and the long switching times that make active 3D difficult) I don't think it would be possible to use the Dolby system in the home, maybe with two single-chip LCD, LCoS or DLP projectors where you can swap out the color wheel.