3d at the cinema

I saw ghosting at Harry Potter and the Deathly Hallows Part II at IMAX.

Both RealD 3D and IMAX 3D are passive 3D systems using polarized light to separate the right from left images steams. Almost alll consumer 3D projectors use an active 3D system with liquid crystal shutter glasses. The passive 3D polarized systems used in theaters would require a screen that retains 100% of the polarized light to be totally free of 3D ghosting. Unfortunately no actual screen can do this. Theaters equipped with the best 3D "silver screen" material will show only minimal ghosting. However, I have been to a couple of theaters that clearly did not have screen materials that could retain polarization very well and as a result there was a lot of visible ghosting with a RealD 3D projections system. With consumer DLP projectors that use active shutter glasses there will only be visible ghosting if either the 3D glasses do not fully block the light when that lens is supposted to be opaque or if there is a synchronization/timing issue between the projector and the glasses. The ability of the screen to retain polarization does not matter as far as 3D ghosting is concerned with such an active 3D system.

One thing to keep in mind is most of the HT projectors will blow away the cinema for 3D. We might talk about how the JVC isn't great at 3D and other PJs do better. Compared to the theater the JVC would blow away most theaters.

A passive 3D system set up well with the right screen will look terrific! I just haven't seen it in most commercial cinemas.

Yes - you see full resolution, i.e., will normally be the same as 2D movies shown in that same theather. The specific resolution will depend on what projector they are using in that theater and the movie itself may be shot/distributed in 2K (with 2+ MPixels images) format or in 4K (with 8+ MPixels images) format. Most digital cinema projectors are either 2K or 4K models.

I went up after watching a 3D movie to observe the 3D projector used at the local AMC Palace theater and it was a Sony. It was a single lens unit and the projector was huge. The unit was projecting two complete images - one above the other onto a "glass" plate. From there the images went on to the screen. This was a Real 3D setup. From what I have read the Real 3D system uses circular polarization. If that is the case I am guessing that the glass plate consisted of two panes - one of which had clockwise polarization and the other counterclockwise.

Have to disagree with the statement about JVC projectors "blowing away" 3D at theaters. The JVC has a lot more problems (flickering and ghosting) with 3D than any 3D presentation I've seen at a movie theater, both IMAX and non-IMAX.

My JVC is pretty good with 3D and I much prefer it over the movie theater, especially for 2D

For 2D I totally agree with you but this is a 3D thread, the JVC has horrible flicker and ghosting in 3D, no movie theater I've ever been in has that kind of flickering and ghosting in 3D...

With that setup you would be half resolution on one axix and full on the other (I had forgot about that RealD setup with the Sony projecctors). The other, more widely used, RealD setup operates a DLP projector at 144Hz and alternates between right and left images (each at 72Hz or 3 times the original movie's 24Hz rate). An electronic controlled "Z-Screen" is used in the light path to alternative between the two polarization orientations in sync. with the projector. This still allows for passive, polarized glasses to be used and you get full resolution to both eyes. Here is the Wiki.

There's more ghosting in the movie theater than on my rs55. I was adding 2d as a side note. And since this is a 3d thread, you should not mention 2D either