It all depends on the model: further on LG passive 3D

Well, there I was, once again incorrectly, thinking that the whole matter of passive 3D was settled. A couple of weeks ago I established, I think, that the current top of the line LG TV, the 55LM9600, uses two different strategies in 3D mode for allocating source lines to display lines.

Some form of line allocation is necessary because only half the number of display lines are available for each eye view as are provided in the source video.

My tests suggested that generally the 55LM9600 used ‘Both Line Allocation‘, but it was clever enough to notice that some content was in the same plane for both eyes, and in such cases it would use ‘Alternate Line Allocation’.

I could tell this because when I took a picture of a diagonal line which I was displaying in 3D in side-by-side mode, when viewed with the glasses on (top, right lens) it was jagged, but without the glasses it was smooth, so all the detail must have been present:

With (top) and without the 3D glasses

But I’m now looking at a considerable less expensive LG 3D TV — still a new model — the LG 55LM7600. Here’s the equivalent from that TV:

Diagonal lines in 3D mode on LM7600 - top through right lens, bottom no glasses

See what I see? Jaggies on the both-eyes-view version at the bottom. This TV clearly used both line allocation for this one (as it did for the alternately coloured line tests, which I checked).

However with the menu from Cats & Dogs: The Revenge of Kitty Galore, this TV delivered full resolution from the flat sections of the picture, even though they were in 3D mode. So it that mode at least, it still seems to have different processing depending on the picture content.

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One Response to It all depends on the model: further on LG passive 3D

  1. Ryan Sandford says:

    Great stuff! What you just pointed out I have noticed in the Soniq of mine using the LG panel. I can see the jaggies close, if its through one or none of the lenses ,mainly in the black on light coloured backgrounds that make the “double” image. But with both, even at close, the detail is filled. When I think about it, I find this method of creating 3D ingenious.I have also found that with more experience watching it makes easier to “process” the image.so to speak, in the sense of no ocular discomfort or headache. Thanks Stephen. 🙂

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