Official AVS Crosstalk Topic - Page 3

Here is the current fall schdule of ESPN-3D college football games:

http://espn.go.com/3d/schedule.html

Not seeing any crosstalk with rechargeble glasses on my un46c7100 from Costco. This is just on 2d to 3d conversion. All I have so far. Dish isn't broadcasting 3d.

Bill, you will on you Samsung once you watch M vs. A in 3D. Had both the7000 and 8000 series LED models. Finally went with Panasonic but it's ghosts on certain scenes also and miis the 2d to 3d conversion feature of which is better on the Samsung vs. the Sony.

I am convinced that most crosstalk is caused by slow ASG.

I tried an 8000, it was totally messed up for 3d. It was generating ghosts itself. When you took off the glasses you could see 3 images!

Panasonic are now selling a $500,000 152" 4k plasma 3DTV. Likely too expensive for anyone here, but there's a blurb in their press release about some new tech in the 3DTV that should reduce cross talk.



Panasonic Press Release

What my previous post is implying is that shutter glasses need to be fancy, while passive polarized glasses don't need to open and close so don't need to be fancy.

If 3D TV is going to work with glasses the ordinary folk will need passive polarized glasses, not active polarized glasses.

If the active polarized glasses do not work then they will distract from the viewing experience, making you feel odd. But passive polarized glasses not having to open and shut will not make you feel odd and so can let you watch 3D for hours on end with no ill effects.

I know active polarized glasses make 3D possible for cheap for the TV, but it makes you feel odd, not good. So fix it or get rid of 3D because feeling wrong because of a gimmick is garbage work.

I can't see any difference between ASG and passive glasses--and the more I use my ASGs the more comfortable they feel.

So you can't see a difference but one is made to feel more comfortable over time (apg), while the other one is automatically comfortably fine (ppg)?

What make/model of Passive 3D glases are you using and how are you getting your TV to polarize the signals so that Active Shutter Glases are not required.
Is it possible that you are confusing the fact that DLP link active shutter glaases are different from IR emitter controlled active shutter glases such as the one in the Mits kit?
in some way?

If the glasses have a half cycle of 1/480 * 1000ms = 2.08333333, and a duty of (1 / 160) * (1000 milliseconds) = 6.25 milliseconds, they can light up in the 2ms and go black for the 6.25ms so neither eye see's any light from the other eyes picture. But since g2g is not certain there is only a approximation of these numbers.

Edit, the above is corrected below
Lights up
1/480 * 1000ms = 2.08333333
Lights down
1/480 * 1000ms = 2.08333333
Duty of holding down shutter
(1 / 210) * (1000 milliseconds) = 4.76190476 milliseconds

You may say the extra time the TV is faster than the glasses is used for blanking out a frame to help with ghosting, but the glasses are lcd so they need that frame that goes blank too in order to completely close, the lcd g2g isn't the same a plasma g2g they (lcd) have to be given some time to completely close. Right now they only have time to open and close and have no blank frame interval to completely go black.

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This is a repost of a earlier reply to this thread, but I'm reposting it so maybe icester can reply to it and verify or prove false the flawed design I think I've found.

Atrue 240 HZ 3D TV refreshs the screen every 1/240 of a second from the contents of the separate display output buffer. If for every real video frame placed in the outuput buffer every 1/240 of a second and following it a Black frame is placed in the ouuput buffer then the 3D TV using 120fps second glases can display 1080p/60 per eye content.

You are confusing frame rate with frame update rate.
240 Hz is just frame update rate and the actual frame rate on the input is 30Hz progressive mode or 60Hz interlaced mode. With 240 Hz the internal image processor creates intermediate differential frames using motion interpolation algorithm. The result is much smoother motion of scenes objects. It acts similar to motion stabilizers used in hand-held camcorders only it is a digital image processing process and mechanical one.
Such 240 Hz display technique is totally incompatible with stereoscopic image display mode such as 120 Hz frame sequential.
One might think why not use it as 240 Hz 3D display mode
which would yield 120 Hz per eye.
Well, the problem is that it is only partial update of a frame
and just a portion of it is refreshed, the portion that has changed only, hence differential frame.
Because the LCD is not capable of refreshing all the pixels in a frame in such short time the techniques can only be used for improved motion performance of 2D movie image sequence.


Mathew Orman

http://www.*******************.com/

Lets make it clear and simple.

LC shutter glasses are not the source of ghosting ever, even if closed at 90% only.
At fault most of the time are: miss-aligned shutter timing, excessively long refresh cycle, excessive Phosphor light emission persistence and finally an extreme view angle such as when corner eyed.

Ghosting AKA crosstalk is often confused with doubled object or doubled scene in 3D content.

To see ghosting one must have only one eye open and if one can spot doubled objects or scene then that is real ghosting. Just remember the doubling is always perfectly horizontal and usually the ghost part of a double is less visible or has less contrast, brightness and color.

Now the difference between ghosting and object doubling.
The ghosting creates flat looking doubled object in both eye, object doubling on the other hand disappears, ones the viewers brain fuses the left with the right part of the double.
Since many of us are new to stereoscopic vision our brains always assume the objects of a scene are at the surface of the screen and for many of as it is often difficult or impossible to focus on something that is not on the surface of a screen. Hence the confusion between ghosting and object doubling.

To remedy this 3D newbie problem nVidia has implemented
object doubling amount control slider AKA 'Stereo Separation' which has a scale from 'Beginner' to 'Advanced'. Unfortunately is is only possible to control real time scene CG generated such as in Games.

For movies the only way for a newbie to reduce object doubling to the fusible level is to move away from the screen or increase screen distance to the point where one can fuse the double object or a double scene.

Finally, simply:

Check for ghosting with one eye closed.
If no ghosting, move away from the screen until you can fuse the scene and it's objects.

One final note:
It is possible due to 3D content defect that some double object or scene are not fusible at all at any distance.
In such case there is nothing that can be done and such content is simply classified as bad or in pro language 'Content with parallax values that are out of limit'.

Happy 3D content viewing!

Mathew Orman

http://www.*******************-usa.com/

I am not sure I agree with you. Many 3D users complained about the 3D scenes such as the Golden Gate bridge over the sunlit bay in MVA. IMHO ghotsing in this scene is casued by the closed eye shutter not being 100% closed and not only because it was on the sceen for a long time.
This Month's Consumer Reports magazine states that crossstalk in 3D programs can be casused by glases that do not keep the content for each eye conpletlly separate( which to me means 100% shutter closure is required) and is most prevelent in scenes with high contrast scenes bright and dark objects.

No,

the reason is that shutter stays ON for to long overlapping refresh period or have misaligned phase.


Mathew Orman

Called samsung support yesterday morning spent 45 min for them to transfer me back and forth between departments to finely have them tell me that they would call me back...they never did...so I called back today they put me on hold then disconeted me three times....ugh. All I know is that my tv gets a lot of crosstalk in the right side of the glasses. I wish that they included a 3d fine tuning in the menu or at least in the serv. Menu... Or let me know if I have to get my tv sent back...I hope not though.


So called samsung and they sent out a couple of old guys.. Not that age matters mind you..but in this case I believe it does. They didn't seem to know Jack. Any case they said they were going to replace the motherboard and emitter on my set but haven't heard back for them. I'm just wondering what if they f*** my tv up even more. Should I try and exchange it at a store that carries the same model . I'm past the 30 day return for bust buy. But I think that Fred myers might exchange it for the same model with out a receipt.. I'm just a little wary about the techs that got sent out...any ideas.

120fps: 1/240 * 1000ms = 4.16666667 milliseconds
60fps: 1/120 * 1000ms = 8.33333333 milliseconds

The TV for LCD 3D is at 240Hz, but the frame blanking means only 120Hz is used to show a picture.
This means a picture is shown by the TV 120 times per second, distributed over both eyes while the person uses the shutter glasses.

The TV is shown a new picture 120 times per second. It does not matter if the picture is making the source at 120 fps:
R1, L1, R1, L1,
R2, L2, R2, L2
Because the TV is displaying 120 new pictures per second, and that is what I want to point out.

This TV with a new picture 120 times per second is too fast for the TV because it's showing 2 pictures every time the glasses are showing one picture.

Again, this is not to do with the source from the hdmi being upsampled to 120fps, I told you the TV is displaying 120 pictures per second. This is nothing to do with the 3D effect the person see's, are we clear on that?

It is understandable that the TV is going to fast so the person see's crosstalk, or two pictures at once when closed one eye and looking at part of movie where they see crosstalk, because there is actually two pictures being shown!

This is not to do with 240Hz but the 120 fps shown after frame blanking. And this is makes the TV show 2 pictures when the glasses show one picture.

Edit, I made a mistake, it's 60fps per eye - 120fps total, so the glasses would be as fast as the tv and not half as fast.

Would the test patterns I made in the stickied thread help the glasses manufacturers fix the on period and misaligned phase problems? I mean if they used my test pattern to calibrate the glasses would that be of help to them?

Yes, but they would not care unless you have a RealD logo on your hut or you last name is Cameron.

Mathew Orman

Put on the glasses upside down, then if you have ghosting on left side that means you have defective LC shutter glasses. If ghosting still on right side then you TV is defective.
Also it is better to complain to the person who sold you the equipment.


Mathew Orman

So are you claiming that it is not neccessary to have glases whose shutters which are not 100% opaque when off to have no crosstalk problems even when watching with one eye?
If this is true what proplems can you have with glases whose lens do not turn 100% opaque when off or what is the minimum opaque % to not have any problems?

I would not waist time talking about the OFF state of LC shutter cell. All ghosting happens only in ON state when the shutter is open or transmissive to light.
The exception are the single filter LC shutter glasses for LCD monitors. Those need to be anligned perfectly horizontal in order not to produce any ghosting.
The advantage of such shutters is zero ambient flicker and
twice higher brightness.

The main difference between LC shutters for DLP and LC shutters for LCD is the additional state where both cells stay OFF for the period that is equal to LCD refresh cycle.
If one attempts to use DLP shutter glasses with LCD
then there will be ghosting becasue the driver is not capable of turning OFF both cells simultaneously.
Another problem with LC shutters for LCD monitor is a requirement of retarder which depolarizes the LCD monitor light to make LC shutter insensitive to horizontal alignment.
The 3D LCD monitors are cheap and bright but 120 Hz is a gimmick of time distributed color dithering and ghost free operation is not possible unless compromised with excessively long OFF period of LC shutter cells.

So, the best is DLP with zero ghosting guaranteed
next is Plasma and LCD is for those who do not mind tweaking at all times and avoiding high contrast images.

Mathew Orman

Of course ghosting can only happed if one set of shuttters is 100% open, however if the other set of shutters is concurently 20% open instead of being 100% closed I submit that ghosting will occur in high contrast scenes.
Why is their no ghosting guarenteed when using an IR emmitter and IR glasses with a DLP. with the Mits 3d adapter kit when used with the MIts 3d DLP TV the emitter and glases are the exact same IR glases that Samusng supplies for their LCD and Plasma 3D TVs with a Mits logo on them instead of a Samsung logo

Because the DLP's DMD micro-mirror pixel has no memory and no delay in response. LCD pixel has memory in form of electric charge that has to be removed and re-polarized on every frame update and at 120 Hz some large charges
that form high contrast areas are updated in time that overlaps the next update and that is why we see ghosting.
As you see the glasses have little to do with ghosting.
But chaining the OFF (opaque) time period to longer can reduce the ghosting at the expense of brightness loss.

Mathew Orman

Black frame insertion was supposed to fix this problem of electrical charge from brightly lit areas.
If Parallel LCD drive circuit architecture is used will the charge you mentioned still be a problem?

Yes, you can completely eliminate ghosting on LCD
either with black frame or longer OFF period on shutters
but it is all at expense of losing brightness and or color performance or increased flicker. Parallel architecture will help some but what would be the most effective is the TN cell its self
should have less capacitance and lighter crystals with less inertia which would allow them to rotate faster with reduced electric filed strength.


Mathew Orman

When you say DLP, is this just for rear projection DLP sets or for DLP front projectors too?

Both, checker board (old) and frame sequential 120 Hz (new one).

Mathew Orman