Perception of Passive 3DTV - A No-Brainer Analogy

[Rodolfo]

In previous articles I described the differences between active-shutter and passive polarized 3D technologies, as well as the subject of “perception” endorsed by the passive polarized 3DTV camp. Graphs and descriptions may get in the way of understanding the concepts so perhaps we should describe the subject of brain perception vs. true image quality with an analogy that may be less complicated than comparing the nuts and bolts of 3DTV technologies, as I did in other articles.

Imagine spending your Saturday visiting new car dealers...

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[terrypaullin]

Excellant analogy Rudolfo. LG is playing to those who are afraid to say (or don't understand) that the King has no clothes ...........

Terry Paullin

[pilothunter]

I have a related question that I have not been able to find an answer for.

First, I have a Panasonic 3D plasma and love the Active 3d glasses and the hi res effect.

The question is, wouldn't it be possible to have this TV (via a software setting) provide an image that can be used for passive glasses?

I have never seen this available, and do not understand why it would not be possible.

I would want this for times when the kids have friends over to watch some 3D movie, and I do not want to supply all of them with active glasses. I would sacrafice the image quality, and have a bucket of passive glasses on hand in this case. Then when the family wants to watch Avatar, we can use the active glasses and have the full 1080 3D resolution.

I know this option is not currently available on my TV, but was just wondering from a technical standpoint if this was possible, and why no one offers such a feature ( a TV that is capable of BOTH active and Passive 3D modes).

I was hoping an expert on this forum may be able to answer this question for me, or point me to a link that explains it.

Thank you

[Rodolfo]

Pilothunter,

Interesting idea, you are no alone, even among the product developers.

A passive glasses 3DTV panel (namely LCD/LEDs) has more than software to make a single 1920x1080 pixel structure be shared for both eyes simultaneously in interleaved lines (1920x540 each), it has a physical film layer on top of its standard LCD screen that polarizes each set of lines (odds to left eye, even to right eye). That film layer is called FPR (Film Patterned Retarder) and cannot be replaced by just software inside an active-shutter panel to make it operate as a passive.

However, a device that sits in front of an existing active-shutter “projector” lens has been introduced early this year. The device polarizes the whole pixel structure of each video frame as they are alternated by the active-shutter style of operation. This will perform the functionality you have in mind (to been able to have a large number of viewers use cheap passive glasses with an active-shutter display), but it covers only the small area of the projector lens, not a whole panel, and requires a special 3D screen that bounces back to the correct eye the polarized light it receives from the projector/device (like the LG passive projector or local cinemas). Here is the link:

http://www.tru3d.com/products/view_prod ... Projectors

And a review of the product:

http://hdguru3d.com/tru3d-allows-any-ac ... #more-2501

Another effort that Samsung and RealD were doing since May 2011 was to make the shutter operation within the TV panel itself and polarize the whole screen alternatively so passive glasses can be used and still have the benefit of full resolution per eye. This “active retarder” would be similar to what an FPR does on a passive set but applied to the whole screen (1920x1080) not just alternated lines (half-resolution of passive technology).

Unfortunately the effort was discontinued recently and the partnership broken, probably due to cost, Samsung did not disclose a reason other than a management direction to support other technologies, including glasses-free 3DTV, but even if that effort would have continued it would have required a new TV set, it was not a device you add to a current active-shutter 3DTV panel, not yet I should say.

Since that active-retarder panel never reached the market I could not verify if the functionality would have allowed a viewer to use the panel also as a regular active-shutter 3DTV with active-shutter glasses if the viewer considered it a better image (in addition to its ability for HDTV of course).

I hope this helps,

Best Regards,

Rodolfo La Maestra

[pilothunter]

Thank you so much for such a detailed and complete reply.

Now I understand the issue much better.

Best regards

[sanjaywable]

You my friend are a life saver. I was full of doubts about a reasonable 3D TV and its features. Now i now what i have to ask for. Thanks to you mate.