Film-Tech Forum ARCHIVE: Question about Dolby 3D and Real D

This is topic Question about Dolby 3D and Real D in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

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Posted by Justin Hamaker (Member # 2165) on 03-11-2010, 04:53 AM:

Do these 3D systems use overlapped images like anaglyph 3D or do they use distinct images for each eye?

Posted by Lyle Romer (Member # 1266) on 03-11-2010, 08:59 AM:

Distinct. They alternate left and right eye 3 times per frame.

Posted by Mark J. Marshall (Member # 1409) on 03-11-2010, 09:52 AM:

Or they can use two projectors and put the overlapping eyes on the screen in sync.

Posted by Julio Roberto (Member # 4976) on 03-11-2010, 10:54 AM:

Yeap.

Some dual-projection (even quadruple projection) Dolby installations put both eyes on the same place at the same time, overlapping.

And RealD XLS does the same on Sony's 4K's.

As does, of course, Imax, Technicolor 3D or dual-systems.

But commonly, RealD, Dolby and Master Image alternate the images "quick enough" to try to make them seem "overlap" (which would be the ideal ...), but they never really do.

XpanD is the only system that can never be used with two images exactly on the same place at the same time, as it defeats the purpose of the system entirely.