DLP 3D resolution question

[bastian74]

I have a samsung 67" DLP RPTV and while in 3d mode with the glasses enabled it seems like there is a checker-board pixel page swap. If I draw a 1 pixel wide line in ms paint at just the right angle I can make it invisible in one eye, and vice versa.

Also, fine writing is broken when viewed through the glasses, but fine when viewed with the naked eye, supporting my observation above.

This says to me that 3d resolutions are half the screen resolution.

This confuses me, since we are page flipping why can't we flip the entire 1080p image for a tru HD resolution 3d image?

My graphics card is a ATI 3870HD, CPU Intel 2.6Ghz quad core.

[nubie]

Yep, these seem to be "checkerboard" in 3D: http://www.tru3d.com/technology/3d_disp ... DTV%20List" onclick="window.open(this.href);return false;


Since DLP works by moving a physical mirror for each pixel (and in most cases a spinning color wheel) I think that the idea is to reduce the speed of the moving parts while keeping a high refresh rate for the glasses.

[bastian74]

Thanks for the lnk. This contained the answer as to why they did what they did.
http://www.dlp.com/downloads/Introducin ... epaper.pdf" onclick="window.open(this.href);return false;

By using a checker-board instead of a ever-other-line method in theory you preserve more detail and can still display images at 60fps (with the screen at 120hz) However any way you slice it you're still loosing just as much resolution as a every-other-line technique. The main benefit is that a thin horizontal/vertical line won't dissapear completely for one eye. However perfectly-alligned diagnal lines still dissapear, and 1-pixel wide writing looks like crap!

However I would have preferred the OPTION to flip the entire screen at 60fps (1080P) with each eye seeing 30fps video, but still flicker-free as the screen would be flipping at 120hz (4 flips per frame of video)

[ssiu]

However I would have preferred the OPTION to flip the entire screen at 60fps (1080P) with each eye seeing 30fps video, but still flicker-free as the screen would be flipping at 120hz (4 flips per frame of video)

The consumer DLP HDTVs do not display a full 1080p image 120 times per second, even in regular 2D mode. It always display half the picture in 1/120 sec, and then the other half in the next 1/120 sec, in checkerboard pattern. Thus the whole 1080p image is only displayed 60 times per second, even in regular 2D mode.

The DLP hardware does "wobulation"; it is intrinsic to how the hardware works. And the S3D support is a natural consequence of this wobulation.

[pixel67]

My understanding is that the HDMI bandwidth is the reason full 1080P Pageflipping doesn't work on these sets. At least that is what i recall reading somewhere. The reason that text looks weird when in 3d mode, say from a website or MS Word, is because it isn't encoded ahead of time with the checkerboard pattern, right? If it were, then the spatial domain sacrifice would be made up for in the time domain through the use of wobulation.