AVS Forum banner
1 - 15 of 15 Posts

·
Registered
Joined
·
182 Posts
Discussion Starter · #1 ·
as above really, i see alot of posts about 3d blurays, tv stations etc, and blaming the content saying it has "terrible ghosting, much worse than xyz".


surely it is the displays fault is there is any crosstalk? I'm wondering if i'm missing something....?
 

·
Registered
Joined
·
407 Posts
Although the majority of crosstalk can be attributed to the display, it also sometimes appears in the content. It's legitimate for someone to say that movie x has more crosstalk than movie y on my display...


I have a DLP so I haven't really seen crosstalk in any of the movies I've watched but in games like Killzone 3, it can get pretty brutal... which is definitely an issue with the content.
 

·
Registered
Joined
·
1,773 Posts

Quote:
Originally Posted by Justin-Dawson /forum/post/20852874


Although the majority of crosstalk can be attributed to the display, it also sometimes appears in the content. It's legitimate for someone to say that movie x has more crosstalk than movie y on my display...

This may turn into a semantics discussion, but technically that's not crosstalk, it's an issue with parallax & convergence.


Crosstalk is a double image resulting from the hardware's failure to adequately separate the left & right views; since this is encoded comletely separately within the content (whether framepacked, SBS, TnB), there is no way crosstalk can result from content.


Your point about games is well taken, and I don't know enough about the platforms in question to confirm that the L/R views are isolated up to the point of display, but I suspect the same is true.


Double images resulting from content are not due to crosstalk, but rather parallax & conversion issues. In other words, if the director or stereo engineer shoot the scene with an object extending past recommended boundaries on the Z axis, or encode the two views too far apart, many people will have trouble converging the two images. Still, the two views remain encoded separately.


You can test whether crosstalk is at play by closing one eye when viewing; if you see double images through one eye, its is crosstalk, and your display or glasses need adjusting. Otherwise, it is convergence.


I think the misunderstanding persists in part due to all the blu-ray reviews that state things like "This title exhibits no apparent crosstalk" (Sorry,Ralph P!). I mean, when reviewing a film, critics don't say, "This movie wasn't projected in reverse"; and for CDs, reviewers don't go out of their way to point out, "This recording doesn't have all the audio coming out of only one speaker"... and that's because (unless there is an egregious error in the transfer) it's not going to happen!


On another note: mods, I think this topic needs a sticky...
 

·
Banned
Joined
·
1,338 Posts
It inherently is an issue with the display unless it is faulty encoded content, like there's a problem with the framepacking on the blu-ray movie.


DLP HDTV's handle the crosstalk issue the best , better compared to LED LCD's and PDP's. With LED LCD's and PDP's crosstalk is more a prevalent issue, especially the former. DLP does 3d in checkerboard format whereas with lcd and plasma it's mostly FS (frame-sequential). Though for 2D HD, lcd and plasma are considered better technology than a dlp, in 3D i think dlp has an advantage.


People who blame content for crosstalk should rather try adjuszting their tv settings and sit at a different viewing angle and see if that makes a difference. Also it is better to avoid any flouroscent light sources directly obstruct your view.
 

·
Registered
Joined
·
1,020 Posts
But I think some movie content gets processed so as to reduce crosstalk on the displays prone to that. Reducing high contrast areas, I think, and maybe something with the color. So some movie content apparently will show less crosstalk than other. I'm a DLPLink guy, so I've never seen crosstalk.
 

·
Registered
Joined
·
1,773 Posts

Quote:
Originally Posted by TrickMcKaha /forum/post/20854182


But I think some movie content gets processed so as to reduce crosstalk on the displays prone to that. Reducing high contrast areas, I think, and maybe something with the color. So some movie content apparently will show less crosstalk than other. I'm a DLPLink guy, so I've never seen crosstalk.

This may be true... I think some content is mastered with active shutter flickering in mind as well, for example, and adjusted to mitigate its potential.


However, addressing and minimizing the potential for issues on particular systems due to the weaknesses & calibration of those systems is very different from those issues being inherent in the content itself.

I am aware of no 3d blu-rays (except anaglyph tech) with crosstalk "baked-in". This would require encoding at least some of the left channel information into the right channel stream, and/or vice versa.


I would assume cable & satellite would also be fairly safe, as I can't see how a left or right eye signal would "bleed" into the other on the transmission end of a SBS or TnB broadcast.
 

·
Registered
Joined
·
511 Posts

Quote:
Originally Posted by thebard /forum/post/20854250


This may be true... I think some content is mastered with active shutter flickering in mind as well, for example, and adjusted to mitigate its potential.


However, addressing and minimizing the potential for issues on particular systems due to the weaknesses & calibration of those systems is very different from those issues being inherent in the content itself.

I am aware of no 3d blu-rays (except anaglyph tech) with crosstalk "baked-in". This would require encoding at least some of the left channel information into the right channel stream, and/or vice versa.


I would assume cable & satellite would also be fairly safe, as I can't see how a left or right eye signal would "bleed" into the other on the transmission end of a SBS or TnB broadcast.


You points all makes logical sense to me, however my personal experience does not prove that to be the case. With my Sony active 3DTV content clearly seems to play a role.


All of the 7-8 blu-ray discs I've tested show minimal ghosting. There is the occasional scene here and there that will show some, but 99% of the time the picture looks perfect. However just about anything I've watched on my cable provider's 3D channel has significant ghosting. Video games as well have a fair bit of ghosting.


My expectation is that if my cable provider showed a 3D movie in SbS format it would have significantly more ghosting than the identical film on blu-ray. I hope to be able to test my theory one day soon, but so far the SbS content broadcast on cable is BRUTAL for crosstalk/ghosting, yet blu-rays looks beautiful.


I'm not sure technically why that would be the case, but it is.
 

·
Registered
Joined
·
2,037 Posts
Quote:
Originally Posted by johnny905
You points all makes logical sense to me, however my personal experience does not prove that to be the case. With my Sony active 3DTV content clearly seems to play a role.


All of the 7-8 blu-ray discs I've tested show minimal ghosting. There is the occasional scene here and there that will show some, but 99% of the time the picture looks perfect. However just about anything I've watched on my cable provider's 3D channel has significant ghosting. Video games as well have a fair bit of ghosting.


My expectation is that if my cable provider showed a 3D movie in SbS format it would have significantly more ghosting than the identical film on blu-ray. I hope to be able to test my theory one day soon, but so far the SbS content broadcast on cable is BRUTAL for crosstalk/ghosting, yet blu-rays looks beautiful.


I'm not sure technically why that would be the case, but it is.
Games have considerably more depth and contrast than movies. That's what causes crosstalk. You might say, "But movies look just as deep as games." But if you take off the glasses and look at how far apart the double images of the deepest background objects are, you'll see that they're further apart in games than movies, and that horizontal spacing is what dictates depth relative to the surface of your screen. You might think that from layer to layer there's enough depth in a movie, but in sheer amount of depth relative to the surface of the screen, videogames are more intense.


Crosstalk depends on the "power handling" of the TV. Think about a speaker and a power amplifier. Think of 3D content as the audio amplifier, and the 3DTV is like the speakers. A speaker distorts if it is fed more power than it can handle, similar to how a 3DTV ghosts when content has more depth and/or contrast than it can handle.
 

·
Registered
Joined
·
1,773 Posts

Quote:
Originally Posted by johnny905 /forum/post/20864380


My expectation is that if my cable provider showed a 3D movie in SbS format it would have significantly more ghosting than the identical film on blu-ray.

But is it actual ghosting, or an issue related to the offset of the L/R views? I suspect broadcast SBS & TnB would be more succeptible to this kind of issue, because the content is half-frame, then stretched to restore proper aspect, then overlayed... and the last steps are done by the display device or processing converter, with no ability to account for underscan, horizontal/vertical image shift, etc., at the source.


I've encountered doubling from broadcast sources as well, but when viewing through one lens it disappears, which indicates that it is due either to excess parallax, or to offset issues, and not true ghosting.
 

·
Registered
Joined
·
747 Posts
When i take off my glasses watching a movie, half the time, theres so little separation, it looks almost like normal 2D. In games, many elements of the scene are separated by inches and it looks like one big blurry mess with the glasses off.


Makes you wonder what these movies would look like with some more realistic separation.
 

·
Registered
Joined
·
511 Posts

Quote:
Originally Posted by thebard /forum/post/20873018


But is it actual ghosting, or an issue related to the offset of the L/R views? I suspect broadcast SBS & TnB would be more succeptible to this kind of issue, because the content is half-frame, then stretched to restore proper aspect, then overlayed... and the last steps are done by the display device or processing converter, with no ability to account for underscan, horizontal/vertical image shift, etc., at the source.


I've encountered doubling from broadcast sources as well, but when viewing through one lens it disappears, which indicates that it is due either to excess parallax, or to offset issues, and not true ghosting.


No, it's definitely ghosting. When I close one eye I clearly see the second image, although somewhat fainter.
 

·
Registered
Joined
·
699 Posts
Content can be made to avoid the crosstalk that is inherent to most 3DTVs. The key is to have the screen objects that are needed to be seen clearly at SCREEN distance. Anything at screen distance will have no parralax. Objects at screen distance will look clear even with the 3d glasses off.


Everything in the foreground and background will be subject to crosstalk from sub-par 3DTVs. Content can be designed so that things in foreground and background are out of focus, and blurry, which diminishes the appearance of crosstalk.


So some content still looks good on 3DTVs that are prone to crosstalk. It is only because of comprimises made in the content.


So yes crosstalk is generated from the display/glasses but content can be made to diminish the effect.
 

·
Registered
Joined
·
747 Posts
Heres what, i think you could call, realistic *window to the world* separation looks like [photo], or close to. Thats a 46" screen and you can see the distant objects are inches apart causing your eyes to look straight on, as they would in real life. You can see how quickly the amount of separation changes on the gun barrel, the laser and the wood planks. Movies seem to have a low amount of separation over the entire screen, at least the ones i've watched. So hopefully they'll solve the crosstalk problem soon. I could imagine some really cool TV productions that would make great use of real looking 3D, like docs on aircraft carriers, mines, caves, travel activites, old cathedrals, etc. Imagine a moving shot of a cathedral going from the floor raising to the ceiling or filming your tour guide from the back of a two seat kayak going down white water in the grand canyon. I would imagine it would look like you were there.


Another problem with crosstalk is a mild blur right? At least on some screens, since i don't think many of the pixels ever fully reach their intended color [that you see], resulting in a reduction in detail and contrast.


 

·
Registered
Joined
·
2,037 Posts

+Realistic depth and scale

-Noticeable crosstalk in several places


+Reduced crosstalk

-Less realistic looking

-Not very practical for videogames


The ideal solution is option 1 in conjunction with a TV that doesn't have major crosstalk problems.


While less than ideal for those who have already invested in a TV that has crosstalk, it's best in the long run to let the content do what it's doing and wait for displays to get better and less expensive.


For now perhaps there will one day be a video processing feature that calibrates the content to your display's performance, dynamically adjusting convergence and employing some kind of selective contrast reduction to things that might otherwise leak through.
 
1 - 15 of 15 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top