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Passive 3D or Active 3D - "True 1080p" aside - Page 3

post #61 of 102

Look again at this example, only this time try to see "through it" so that the two images overlap.  You'll see the "P" hover in front of the house.  Or if you cannot see through it, try crossing your eyes to reverse the convergence.  You'll see the P somewhat behind the house:

 

          H              H
         H H            H H
        H   H          H   H
       H     H        H     H
      H       H      H       H
      HHHHHHHHH      HHHHHHHHH
      H       H      H       H
      H       H      H       H
      H       H      H       H
      H    P  H      H  P    H

 

But try that now.  You cannot.  The H's will fuse, but the P's will never make any sense:

 

          H              H
         H H            H H
        H   H          H   H
       H     H        H     H
      H       H      H       H
      HHHHHHHHH      HHHHHHHHH
      H       H      H       H
      H       H      H       H
      H       H      H   P   H
      H   P   H      H       H

 

If you focus on the fused H's, the P's will now sit in odd relation to each other.  One belongs to one set of H's and the other belongs to the other, and they're appearing one above the other and your brain is pulling its hair out trying to make sense of it.  You can get an almost "floaty" look to it, but that's not 3D.  That's not even "almost 3D".  It's two floaty half P images or something.

 

Now for fun, tip your head to the left slightly, maybe 10°.  You'll be able to fuse the P's, but the H's will be out of whack.


Edited by tgm1024 - 10/2/13 at 2:13pm
post #62 of 102
Most 3d forces one's eyes to cross or converge towards the center, which is not necessary, but happens when one's brain receives the two perspectives. The brain tries to accomodate what the eyes are showing it.

When one watches sideways, one's eyes are ON the center line, and can't cross, so if anything, one should feel no eyestrain at all.
post #63 of 102
Quote:
Originally Posted by Augerhandle View Post

Most 3d forces one's eyes to cross or converge towards the center, which is not necessary, but happens when one's brain receives the two perspectives. The brain tries to accomodate what the eyes are showing it.

When one watches sideways, one's eyes are ON the center line, and can't cross, so if anything, one should feel no eyestrain at all.

 

That would be the case if all you saw were dual images for everything, but on the side you will have something close enough to overlap.  It just can't be in z-axis relation to anything else.  This will cause your brain to keep trying, and (in my experience) keep attempting to reacquire different pairs of images to make it "work".

post #64 of 102
Quote:
Originally Posted by tgm1024 View Post


Basically what I am saying is that the assumption you lose stereo ability when you lay down and watch 3D TV is based off the assumption that stereo vision is based on a direct left right offset from your eyes right?

And the cartoon above illustrates a conception that if you don't have only left right separation, the 3D effect will not work, hence the need for the weird eye gymnastics illustrated right?

The assumption being that as you tilt your head, your eyes stay left right separated from each other, so you still get only a left right separated image pair from them right in real world normal site right?

But that's not how it really works smile.gif

As you tilt your head, your eyeballs rotate in their sockets to stay level as long as possible. So you end up with image pairs that are not left right separation only - but rather left right and up down separated.

This means your brain is able to get 3D information even when the data difference is not just right left separation..

I don't think your brain works like a math chip on a computer that can only work if data is input in the proper order and it gets the expected data types.

I think just like if you wear glasses that invert your vision, your brain eventually adjusts, it can adjust to things like parallax separation in the vertical plain.

In essence it can take two images and see them for what they are, adjust them as necessary and get get the 3D data from them. If it means essentially rotating them in your brain so the separation becomes left right again then your brain can do it.



As for the 2D stereo it si not impossible to get 3D image info from 2D image via stereo glasses... it would just happen only specific circumstances... it wouldn't be REAL 3D info of course (unelss the 2D image was somehow built for the purposes which violates the point we are talking about). But just like your brain is great at seeing faces where there aren't any, it's great at trying to figure out depth everywhere it can.

I would posit that when you look at something like a 2D picture, your brain recognizes a perfect match of image data from both eyes and knows it's 2D.

But when the eyes get mis matching data, it assumes it's 3D and tries to get 3D information out of it even if there isn't really any there to get.

So in the case of 2D image through glasses - your brain recognizes that it's getting 2 image sets that are slightly different but very similar. In real life this tends to mean there is 3D data to be extrapolated here.

It does it's best and what you end up with is a warped, sometimes KIND of weirdly not 2D thing.

Just like many optical illusions trick your brains attempt to extrapolate 3D data when there is a lack of 3D data, however in this case there isn't any cute illusion to realizes, just a mess as your brain does the best it can with data that will never really fit right.
post #65 of 102
For what it's worth, passive TV's use circular polarization, so there is no crosstalk when you tilt your head. IMAX 3D is linear, which yields crosstalk if your head isn't straight.

Your brain can comprehend the stereo image for a while but it's going to make less and less sense as you tilt past 45 degrees.
post #66 of 102
Quote:
Originally Posted by cakefoo View Post

For what it's worth, passive TV's use circular polarization, so there is no crosstalk when you tilt your head. IMAX 3D is linear, which yields crosstalk if your head isn't straight.

Your brain can comprehend the stereo image for a while but it's going to make less and less sense as you tilt past 45 degrees.


I pointed out circular polarization in post #54 above, but it's not at issue here.  The circular polarization doesn't help you with the stereo left / right information not being there.  It's just not swapping eyes the way a linear polarization filter does.  Plus in linear, you do get incremental crosstalk the more you're off from level.  But circular or not, it's not a crosstalk issue at all.

 

Devedander, I'm afraid you still don't understand "how it works" as you put it.  You're still not following the issue.  But I've run out of ways of explaining it.

 

Yes, during a tip, for a very small amount of angle your eyes will attempt to stay level to fuse the information.  But that attempt of your eyes to stay individually level has nothing to do with whether or not the offset information is there properly in the first place.  None.

 

In the example I gave, the distance from the person to the roof of the house for one eye has been squeezed.  Your brain has NO WAY of understanding this, *NONE*.  Not "a limited way", not a "hard time with", but no way at all of interpreting that the person closer to the roof in one eye compared to the other eye is in any way a change in the Z axis.  That's a vertical change.  Your eye/brain neurology has no ability to make sense of it.

 

It *does*, however, understand a change in left and right.

 

Because your eyes are left and right.  You cannot get past that, even if they were able to independently move up and down yet independently level.


Edited by tgm1024 - 10/7/13 at 2:29pm
post #67 of 102
Quote:
Originally Posted by tgm1024 View Post


I figured pictures would make it easier:

This is normal stereo vision we all think of, level head:



And when you tilt your head, the assumption is this is the stereo pair you see:




Right? Left eye and right eye remain even and you get left right parallax.

But it's not...

What you really see is more like this:



Because as I noted your eyeballs rotate to try and stay level as your head tips. Your right eye (in this case green) is higher than your left eye, but they stay level.

What does this mean? It means your brain is getting stereo info from images that are not left right only parallax.

Now when you lay down and watch the assumption again is that your eyes see this:


Now even if they WERE seeing that, we have already seen that your brain does not only work in left right only parallax but can interpret data which involves some up/down shift.

But again your eyeballs are straining in your head to be as level as possible so what you really see is more like this



Which you will note is kind of similar to what we see above in the actual head tilted view.

So the point I am trying to get to is:

The assumption that you always interpret 3D information from a let right parallax only standpoint is incorrect.

Thus using it as the assumption you cannot interpret 3D from an up/down parallax is fallacious.


EDIT now I see your previous post, basically I am saying:

:"That's a vertical change.  Your eye/brain neurology has no ability to make sense of it."

I do not think that is necessarily true. I think your brain is indeed capable of making some sense of it, perhaps it's just less practiced at it and that's why it feels strange, but it's not impossible to do. Left right is what we do best and most naturally/commonly, but I think up/down parallax might be like writing with your non dominant hand - not as good, not natural, but doable to an extent.

If it were, in the even of a tilted head (where your eyeballs stay level) you would experience at least some loss of depth perception. Since we all tilt our heads on a regular basis, I can't imagine this is true.

Basically what I am saying is that your brain does not work like a computer and does not take pixel 200,500 in your left eye and only search the 500 line of your right eye for a correlating one to determine depth.

I posit your brain interprets the entire image, recognizes each item in the image and notices that there is different information for the same item from different eyes and does it's best to determine depth from this disparity.
Edited by Devedander - 10/7/13 at 4:05pm
post #68 of 102
Quote:
Originally Posted by Devedander View Post

If it were, in the even of a tilted head (where your eyeballs stay level) you would experience at least some loss of depth perception. Since we all tilt our heads on a regular basis, I can't imagine this is true.

 

Yes, and this misunderstanding of yours is precisely what I've identified it to be.  Especially solidified by the images you posted above.

 

Look at it this one final way.  Compare a TV to real life.  Let's make it as similar as possible.

 

1. If you look out a window surrounded by a TV bezel to the scene outside, as you tip your head your left and right information has moved such that the new left and right information is at angle.  Your eyes are now at angle, and all the objects are similarly preceived at angle and the information is received just as it normally is.

 

2. If instead you look at the same TV bezel that is actually a 3D display showing a 3D movie of the same outside, that movie was captured with two cameras, positioned left and right of each other that never change their orientation.  As you tip your head to the left, the information does not change with the orientation of your eyes.

 

Quote:
Basically what I am saying is that your brain does not work like a computer and does not take pixel 200,500 in your left eye and only search the 500 line of your right eye for a correlating one to determine depth.

Complete red herring.  No one is implying this.
 

Quote:
I posit your brain interprets the entire image, recognizes each item in the image and notices that there is different information for the same item from different eyes and does it's best to determine depth from this disparity.

Again, you're being fooled by a common intuitive look at a 3D display.  But it's incorrect.  At first brush to most people it seems that your brain is receiving a complete 2D image for the left eye, and a complete 2D image for the right eye, and as you tip your head, each 2D image tips, and the 3D information goes with it just like in real life.  However this is not the case.

 

Sitting level, as TV 3D items move along the Z axis, they are moved left and right closer and apart from each other when comparing left eye to right eye.  Get clear on this first.  Take the glasses off.  If you were to look at a  display with 3D enabled without glasses, and a ball is thrown toward or away from you you would see the ghosts of the ball move L/R closer or further away from each other.  Left and right.

 

Sitting at 90°, (without glasses) you would see that ghost move closer or further away to each other vertically.  It's not the same as you tilting your head in real life, where the left and right offset information to the eye moves with the eye position.

 

Look, you've fallen into a very common trap here and have your intuition set wrong.  I've explained it every way I can.  I invite someone else to try to explain it further to you, but I'm exhausted with it.  I'll need to leave it with "believe what you want".  Not a comfortable stance for me, but it'll have to do for now.

 

 

Peace.

post #69 of 102
This is a complicated but interesting discussion!

I have to say I agree with tgm1024's line of thinking here. While our eyes can indeed rotate a bit, the problem is still that the 3D TV doesn't provide the two images your brain expects to see in that orientation. To match Devedander's images above, the cameras that shot the movie would have to similarly tilt and rotate. Obviously, that's not possible, and so we see an "impossible" pair of images.

I think we're in agreement though that tilting your head while watching 3D is not ideal. It's more work for your eyes/brain which I would expect means a higher likelihood of eye strain and headaches, and deliver a less cohesive, less satisfying 3D image.
post #70 of 102
Quote:
Originally Posted by Airion View Post

This is a complicated but interesting discussion!

I have to say I agree with tgm1024's line of thinking here. While our eyes can indeed rotate a bit, the problem is still that the 3D TV doesn't provide the two images your brain expects to see in that orientation. To match Devedander's images above, the cameras that shot the movie would have to similarly tilt and rotate. Obviously, that's not possible, and so we see an "impossible" pair of images.

I think we're in agreement though that tilting your head while watching 3D is not ideal. It's more work for your eyes/brain which I would expect means a higher likelihood of eye strain and headaches, and deliver a less cohesive, less satisfying 3D image.

 

Always think back to the cameras and what the information is.

 

I can't wait to see what happens as we get closer and closer to rendering 3D CGI movies in real time.  Imagine looking around Pandora during the movie Avatar.  (Using iPads at various angles, or VR headsets).

post #71 of 102
Quote:
Originally Posted by tgm1024 View Post

Quote:
Yes, and this misunderstanding of yours is precisely what I've identified it to be.  Especially solidified by the images you posted above.

Look at it this one final way.  Compare a TV to real life.  Let's make it as similar as possible.

1. If you look out a window surrounded by a TV bezel to the scene outside, as you tip your head your left and right information has moved such that the new left and right information is at angle.  Your eyes are now at angle, and all the objects are similarly preceived at angle and the information is received just as it normally is.

2. If instead you look at the same TV bezel that is actually a 3D display showing a 3D movie of the same outside, that movie was captured with two cameras, positioned left and right of each other that never change their orientation.  As you tip your head to the left, the information does not change with the orientation of your eyes.

Complete red herring.  No one is implying this.

 
Again, you're being fooled by a common intuitive look at a 3D display.  But it's incorrect.  At first brush to most people it seems that your brain is receiving a complete 2D image for the left eye, and a complete 2D image for the right eye, and as you tip your head, each 2D image tips, and the 3D information goes with it just like in real life.  However this is not the case.

Sitting level, as TV 3D items move along the Z axis, they are moved left and right closer and apart from each other when comparing left eye to right eye.  Get clear on this first.  Take the glasses off.  If you were to look at a  display with 3D enabled without glasses, and a ball is thrown toward or away from you you would see the ghosts of the ball move L/R closer or further away from each other.  Left and right.

Sitting at 90°, (without glasses) you would see that ghost move closer or further away to each other vertically.  It's not the same as you tilting your head in real life, where the left and right offset information to the eye moves with the eye position.

Look, you've fallen into a very common trap here and have your intuition set wrong.  I've explained it every way I can.  I invite someone else to try to explain it further to you, but I'm exhausted with it.  I'll need to leave it with "believe what you want".  Not a comfortable stance for me, but it'll have to do for now.


Peace.

Quote:
Originally Posted by Airion View Post

This is a complicated but interesting discussion!

I have to say I agree with tgm1024's line of thinking here. While our eyes can indeed rotate a bit, the problem is still that the 3D TV doesn't provide the two images your brain expects to see in that orientation. To match Devedander's images above, the cameras that shot the movie would have to similarly tilt and rotate. Obviously, that's not possible, and so we see an "impossible" pair of images.

I think we're in agreement though that tilting your head while watching 3D is not ideal. It's more work for your eyes/brain which I would expect means a higher likelihood of eye strain and headaches, and deliver a less cohesive, less satisfying 3D image.

Quote:
Originally Posted by tgm1024 View Post

Always think back to the cameras and what the information is.

I can't wait to see what happens as we get closer and closer to rendering 3D CGI movies in real time.  Imagine looking around Pandora during the movie Avatar.  (Using iPads at various angles, or VR headsets).

I agree that the cameras do not supply the information your brain is used to receiving in the way it's used to receiving it, but this all falls back on lack of any proof that this statement is true:

"That's a vertical change. Your eye/brain neurology has no ability to make sense of it."

Are there any studies or tests that have been done to prove this or is this just logic based on the fact that it normally operates on a left/right parallax so we assume it cannot operate in any other way.

What tgm identified above as a red hearing really isn't... there are two possibilities:

1: Your brain/eyes can only interpret 3D from left/right parallax stereo

2: Your brain/eyes can interpret 3D from images not necessarily left/right stereo


If 1 is true then there is no way lying down 3D works. Which I find unlikely because emperical evidence (ie my eyes and my TV) says otherwise.

If 2 is true then it opens the doors for vertical parallax depth perception and since you can definitely determine depth outside of just left/right parallax (ie tilted head but level eyeballs) I lean towards this.

I think a simple test would be to manufacture a few side by side test images. Include some simple shapes that are the same size in all images however vary their depth between images. Now view these while lying down.

If you can correctly identify which is in the foreground vs background then depth can be perceived from vertical parallax.

I wish I had spent my time doing that instead of red and green squares but if anyone can make this test I think it would be a way to put this to be once and for all.

If not I can probably whip these up later this week...

Again I ask, has anyone challenged the notion your brain simply can't work outside left right parallax or are we all just assuming it is true?
post #72 of 102
I think the piece you're missing is convergence. If you have vertical parallax, then your eyes would need to move up and down separately to converge on objects in the foreground. Can our eyes do that?
Edited by Airion - 10/7/13 at 7:13pm
post #73 of 102
Just like the interlaced argument, these technical debates become a huge waste of time and brain cells.

The fact of the matter is that, as a result of my own testing, I now understand that -some- head tilt (maybe 30-45 degrees) can be tolerated as my brain still understands the convergence and occlusion cues it's receiving.

I just wouldn't subject myself to it for any significant length of time like Augerhandle would, because misaligned 3D is one of the main causes of discomfort.
post #74 of 102
Quote:
Originally Posted by Devedander View Post

I think a simple test would be to manufacture a few side by side test images. Include some simple shapes that are the same size in all images however vary their depth between images. Now view these while lying down.

If you can correctly identify which is in the foreground vs background then depth can be perceived from vertical parallax.

I wish I had spent my time doing that instead of red and green squares but if anyone can make this test I think it would be a way to put this to be once and for all.

If not I can probably whip these up later this week...

Again I ask, has anyone challenged the notion your brain simply can't work outside left right parallax or are we all just assuming it is true?
Instead of overcomplicating things by authoring a test pattern, just watch 3D content on your tv with your head tilted. We don't watch test patterns leisurely, we watch movies and games.
post #75 of 102
Quote:
Originally Posted by Airion View Post

I think the piece you're missing is convergence. If you have vertical parallax, then your eyes would need to move up and down separately to converge on objects in the foreground. Can our eyes do that?

No but the assumption they would have to is again based on the theory that they can ONLY work the way they NORMALLY work.

Again if it was not possible to see convergence due to up down parallax, then when you tilt your head in normal life you would lose depth perception (as your eyeballs roll creating an up down parallax difference)
Edited by Devedander - 10/8/13 at 9:24am
post #76 of 102
Quote:
Originally Posted by cakefoo View Post

Instead of overcomplicating things by authoring a test pattern, just watch 3D content on your tv with your head tilted. We don't watch test patterns leisurely, we watch movies and games.

2 reasons

1 The very existence of this debate even after several people have said they indeed can see 3d lying down proves that just saying let's pay attention to what we see isn't enough

2 This is not complicating it but isolating the issue in question. We get depth queues in many ways other than convergence and occlusion. Even in 2d we can extrapolate depth information from a lot of things as size, shading, contrast etc. Its why I can tell a person is closer than a tree in a photo. By using real life images to test this particular question you introduce issues that give false results. I may THINK I can determine depth laying down from stereo when really I am determining depth from other queues and applying that depth info to what I see.

I mean this is AVSforum... we live in the world of test patterns BECAUSE we know you cannot rely on subjective feedback. Otherwise no one would spend money on color sensors and light meters... we would all just look at real world pictures and decide what looks good/bright.
Edited by Devedander - 10/8/13 at 9:26am
post #77 of 102
Quote:
Originally Posted by Devedander View Post
 
Quote:
Originally Posted by Airion View Post

I think the piece you're missing is convergence. If you have vertical parallax, then your eyes would need to move up and down separately to converge on objects in the foreground. Can our eyes do that?

No but the assumption they would have to is again based on the theory that they can ONLY work the way they NORMALLY work.

Again if it was not possible to see convergence due to up down parallax when you tilt your head in normal life you would lose depth perception (as your eyeballs roll creating an up down parallax difference)

 

 

I keep foolishly coming back into this because I keep becoming convinced that I can get you to visualize why real life isn't hampered by the constrains that TV 3D is.  It always looks like you've narrowed it down to a single misconception that can be cleared up.

 

There is no up/down parallax relative to your eyes when you tip your head in real life.  The paralax is FORMED BY YOUR EYES.  When your eyes tip, what is defined as "left/right" goes with it.  If you want to think in mystic terms: It would be no different from grabbing the world in front of you with magic gloves and rotating it to the side.

 

HOWEVER, in a 3D movie(etc.), the paralax is formed by the cameras.  No one tipped the cameras on top of each other because someone decided to lie down on their couch.


Edited by tgm1024 - 10/8/13 at 11:44am
post #78 of 102
Quote:
Originally Posted by Devedander View Post

Again if it was not possible to see convergence due to up down parallax, then when you tilt your head in normal life you would lose depth perception (as your eyeballs roll creating an up down parallax difference)
In real life, our eyes send an image to the brain based on the orientation of our head. When we tilt our head, the left and right eyes go with it in unison. The eyes, brain and skull are all attached to each other, so there is never a conflict or misalignment.

With 3DTV the source images are recorded by two cameras on a fixed horizontal axis. The cameras serve as eye signals that are fed to our brain and override what our own eyes see. But when we roll our heads in front of a 3DTV, the images tilt in the opposite direction and if we tilt completely sideways, the LR images become top to bottom, which conflicts with the human left-right eye position. We can tolerate tilt to a certain degree though.
Edited by cakefoo - 10/8/13 at 11:11am
post #79 of 102
Quote:
Originally Posted by tgm1024 View Post

There is no up/down parallax relative to your eyes when you tip your head in real life. 

Quote:
Originally Posted by cakefoo View Post

The eyes, brain and skull are all attached to each other, so there is never a conflict or misalignment.

I know you are both deadset on figuring out why I can't grasp this simple point, but you are so set on doing so you are completely missing the very simple point I am making:

What you both said above is not true.

tmg there IS up down parallax (some) in real life.

Cake your eyes are NOT attached to your skull (at least not in the way your headlights are attached to your car).

That's what I am getting at with all this eyeball roll and diagrams...

This is what it comes down to, cakefoo made the perfect example when he says your eyes are attached to your skull so stay left right aligned when you tilt yoru head.

They don't.

Again it comes down to eyeball roll.

Again when you tilt your head, if your eyes really WERE attached to your skull, they would stay level with your jawline and not the horizon. Thus if you tilt your head to the left, the left eye is lower than the right and the image each sees is a perfect horizontal pan from the other like this:



Both eyes tilted and properly left to right separated. But that's not what happens.

As you tilt your head to the left, both eyes rotate in your skull so they are no longer aligned with your jawbone, they remain aligned with the horizon (obviuos to a point, they don't roll a full 90 degrees or anything). Your right eye ends up higher than your left and both capture images even with the horizon - or in other words vertically offset. What you really see is more like this:



(note both sets of pictures are supposed to be left right pairs but due to formatting they may show up over each other)

"But that's not at all what I see!" I hear you exclaim. "I do not see the world as still level!"

Your eyes do. I assure you, if you think about it for just a moment (let go of your certainty that you are right about how your eyes work and follow the logic of rotating eyeballs and tilted head). But your brain, using information from your ears for balance and it's own knowledge of how your body is moving corrects for this. Thats the point I am making all along: Your brain is good enough to do more than simply look at a left right parallax and draw depth, it does much more manupilating and thats why I beleive it's entirely possible it can go all the way to up down parallax to draw depth data.

Here is one last attempt to illsutrate this so there is no confusion. The face on the left is what we normally are doing, level head, eyes both parallel to the horizon each capturing a true left right parallax offset image. The middle is what you both assume is happening when you tilt your head, head tilted, eyes staying level with the tilt of the head. On the right is what really happens: Head tilts, eyes roll to stay level with horizon, you end up with one camera effectively above and to the side of the other creating both horizontal and veritcal parallax offset from each other.



Please excuse my hideous MS Paint skills. The red lines represent the orientation of each eye interms of what it woudl individually see as "horizontal".

Cakefoo I believe you do 3D photography. You have two cameras stuck together side by side right? And when you tip them, they do what the middle face does right? Take one and lower it compared to the other to capture what the right hand face would see. Tell me there is no up down parallax there.

Now think about this... if your brain can fix that so smoothly you had no idea it even happened until I explained it all to you, isn't it possible it can go even further?
post #80 of 102
I don't think we disagree with you that some tilt is tolerable. It's straining, but tolerable. But more than a little and I find the stereoscopic image falls apart. At 90 degrees, I see double images. I think the bottom line is that watching 3D TV with your head tilted is not recommended, even if it is possible.
Quote:
Originally Posted by Devedander View Post

No but the assumption they would have to is again based on the theory that they can ONLY work the way they NORMALLY work.

(That was in response to me asking if our eyes can converge by one eye moving up and the other moving down.) Isn't convergence a requirement for stereoscopic 3D? If your answer is that no, they can't converge, then it's not stereoscopic 3D. It is what you describe here:
Quote:
Originally Posted by Devedander View Post

We get depth queues in many ways other than convergence and occlusion. Even in 2d we can extrapolate depth information from a lot of things as size, shading, contrast etc. Its why I can tell a person is closer than a tree in a photo. By using real life images to test this particular question you introduce issues that give false results. I may THINK I can determine depth laying down from stereo when really I am determining depth from other queues and applying that depth info to what I see.

Essentially the image is no more 3D than regular 2D images. What 3D TVs offer is stereoscopic 3D. If you tilt your head so far that you can no longer fuse the images for stereoscopic 3D, then there's no point it watching it in stereoscopic 3D mode.
Edited by Airion - 10/8/13 at 6:49pm
post #81 of 102
Quote:
Originally Posted by Devedander View Post

As you tilt your head to the left, both eyes rotate in your skull so they are no longer aligned with your jawbone

 

Where did you get this idea from?  That's not what happens at all.

post #82 of 102
I've been researching a bit about how able our eyes are to fuse vertically, as they would need to if you watched a 3D TV with your head tilted 90 degrees (turning the horizontal disparity to vertical relative to the orientation of your head). Our eyes can in fact do it, but not much.

According to the pdf here: http://www.cse.yorku.ca/percept/papers/jist%20paper.pdf

Page 11, under "Fusion of Vertical Disparity," it says that up to 30 arc minutes can be tolerated. Converting that to degrees, it's 0.5 degrees.
post #83 of 102
From http://www.ncbi.nlm.nih.gov/pubmed/11867581:

"RESULTS:A consistent ocular counterroll corresponding to the amount of head tilt was observed in all subjects. Maximum torsional amplitude was 10 degrees at a 45-degree head tilt. The relative amount of compensation ranged between 13% and 22% of the actual head tilt, decreasing with increasing head tilt."

So while our eyes roll when we tilt our heads, they only compensate a very small amount. Devedander's illustration a few posts above (the rightmost depiction) would appear to be largely incorrect. This seems to agree with what I found above, that we can fuse only a small amount of vertical disparity.
post #84 of 102
have any of you interested in the best 3d possible looked over at this thread ? http://www.avsforum.com/t/1407101/official-omega-3d-passive-projection-system-thread or this one http://www.avsforum.com/t/1280393/the-ultimate-3d-projection-system-a-practical-discussion-thread

far better than any theater and far better than the drawbacks of shutter / active glasses or passive polarizing tv sets. no ghosting at all , no head tilting issues ( with the omega 3d at least ) , no flicker, bright full color 3D . its not for everyone for sure but the initial thread title says it all, the "ultimate" passive 3d system.

most users working on dual passive 3d systems were looking for better performance of 3d than one gets from active glasses or polarizing systems that have flicker.
post #85 of 102
Quote:
Originally Posted by motorman45 View Post

no head tilting issues

You should read the past few pages of posts instead of just skimming them. Or at least, join the debate instead of blindly advertising.
post #86 of 102
Quote:
Originally Posted by Airion View Post

From http://www.ncbi.nlm.nih.gov/pubmed/11867581:

"RESULTS:A consistent ocular counterroll corresponding to the amount of head tilt was observed in all subjects. Maximum torsional amplitude was 10 degrees at a 45-degree head tilt. The relative amount of compensation ranged between 13% and 22% of the actual head tilt, decreasing with increasing head tilt."

So while our eyes roll when we tilt our heads, they only compensate a very small amount. Devedander's illustration a few posts above (the rightmost depiction) would appear to be largely incorrect. This seems to agree with what I found above, that we can fuse only a small amount of vertical disparity.

 

Yes, and you've parsed and filtered this out well.

 

That eye-independent shift upwards and downwards to maintain a lock (implemented as a miniscule roll when you view the tilt as about a z-axis) is a known phenomenon, but it's one that I believe Devedander is extrapolating upward to a sort of standard full degree mechanism.  Two problems there:

 

1. It's not a full degree mechanism and is not what happens to any appreciable degree every time you tilt your head.

2. Even if it was, it does not involve 3D perception at all once you've exceeded the left/right information.

 

You can engage that roll by locking each eye to an independent image (NOT by staring at something IRL), and artificially shifting one image upwards by tiny amounts.  Your eyes will try to break their horizontal to continue the fuse to an incredibly miniscule degree.  This is entirely a red herring to what we're talking about, and is skewing the conversation off track.

 

Look at two small identical photos side by side.  Cross your eyes (or look through it) to overlap them perfectly.  Now slowly tilt your head.  Your brain will painfully try to connect them for a very very small vertical disparity.  Now do the same with two side by side 3D images.  Your brain will similarly try to connect them (briefly), but even if it could to 90°, the 3D information is lost.

 

That fusing has absolutely nothing to do with Left/Right information, and does not change the fact that when you tilt your head in real life you're now re-aligning what that "horizontal" is and (again IRL) don't lose Left/Right information.

 

Recap here, (and please take note of this!), that "fusing" will fuse an image to a degree but impart absolutely NO 3D INFORMATION.  Fusing two images together does not mean 3D information has magically shown up.

 

Guys, I'm unsubscribing from this thread until this circle of misinformation stops.  I lack the temperament for this kind of thing.  Isolated to that alone, I accept that as my failing not any of yours, but for me personally I find it exhausting and I've significantly lost any semblance of a "high road" tone in this, for which I'm sorry.

post #87 of 102
im sorry , i did read most all of the thread but looking at the issue from the original poster and the intent of the thread i thought it was good to show what ohers who have looked at this issue and found other options had to say.
where the thread ended up with the issue of head and image shift /paralax , and the ammount of image paralax in any direction is a deep topic. one of my hobbies is taking 3D photographs and digital processing of them. ive had more than one person ask me about image paralax and how much virtical paralax is tollerable. not much. it easy to test with some anaglyph images. just look at youtube for some gopro videos and you will find several with a virtical missmatch that is hard to look at, tilting your head while looking at a well made stereo image is another thing.
most of this is in what you have been taling about at the end of this thread.
you dont need two cameras to make stereo images. a slide mount on a tripod and a decent digital camera are all you need. you just adjust the camera movement / offset depending on the distance to the focus image ( 1/30th) . anyone can do it. and you can use free anaglyph image making apps on the web to test them out. you could answer your own thoughts on all these by trying it out.

im not blindly advertising, im not trying to advertise at all, it is my hobby to build 3d systems of all types including working on a passive led tv and projection systems aside from 3D image creation. i appologize for any appearance of promotion. not my intent here
post #88 of 102
Speaking generally, if you find this discussion to be a waste of brain cells or aggravating then of course you shouldn't be visiting this thread.

I think Devedander is largely mistaken on this topic, but I'm learning a lot. Previously I didn't think it possible that our eyes could rotate in their sockets when we tilt our heads. Now I know it does in fact happen. How much? Well, as much as I described in my posts above. Upon being challenged to research, I learned a lot about the advantages and disadvantages of parallel vs converged stereoscopic cameras, in addition to the question at hand.

This is good science. Discuss, debate, and doubt. If you still disagree with the topic at hand, at least you'll learn something along the way, or learn how to better express and convey your argument. So I'd just encourage people to embrace the debate and participate rather than get frustrated. If it was uncivil then I would understand, but it isn't.
post #89 of 102
Quote:
Originally Posted by motorman45 View Post

one of my hobbies is taking 3D photographs and digital processing of them. ive had more than one person ask me about image paralax and how much virtical paralax is tollerable. not much.

Likewise I apologize that my previous response was a bit snippy, but in the context of the current discussion it seemed like you were claiming the impossible, that the Omega 3D system resolved the head tilt/vertical parallax problem that is inherent to 3D displays.

I also take 3D photographs, and one of my biggest challenges is getting the camera perfectly level when I take a picture. A lot of my photos are nonetheless slightly misaligned. I find my eyes can deal with a little vertical disparity, but certainly not a lot. Even a little seems to increase discomfort.
post #90 of 102
Quote:
Originally Posted by tgm1024 View Post

Where did you get this idea from?  That's not what happens at all.

Pretty sure it does... as I have said repeatedly go try this:

Look at your own eyeball in a mirror (probably best to pull your eyelids apart with your fingers to see more of your eye)

Find a spot or blood vessel on it and not it's location in relation to something like an eyelash.

Tilt your head to one side.

You will notice your eye does not rotate in unison with your head for several degrees.

This is called occular torsional rotation.

Now this doesn't mean your eyes do barrel rolls in your skull or anything, but your eyes do rotate to a point to try and stay level as you tilt your head.

Again I think you have been so keen on making your point to me you have been completely ignoring this very pertinent point (calling it a red hearing at one point) that I keep trying to make....
Quote:
Originally Posted by tgm1024 View Post

Yes, and you've parsed and filtered this out well.

That eye-independent shift upwards and downwards to maintain a lock (implemented as a miniscule roll when you view the tilt as about a z-axis) is a known phenomenon, but it's one that I believe Devedander is extrapolating upward to a sort of standard full degree mechanism.  Two problems there:

1. It's not a full degree mechanism and is not what happens to any appreciable degree every time you tilt your head.
2. Even if it was, it does not involve 3D perception at all once you've exceeded the left/right information.

You can engage that roll by locking each eye to an independent image (NOT by staring at something IRL), and artificially shifting one image upwards by tiny amounts.  Your eyes will try to break their horizontal to continue the fuse to an incredibly miniscule degree.  This is entirely a red herring to what we're talking about, and is skewing the conversation off track.

Look at two small identical photos side by side.  Cross your eyes (or look through it) to overlap them perfectly.  Now slowly tilt your head.  Your brain will painfully try to connect them for a very very small vertical disparity.  Now do the same with two side by side 3D images.  Your brain will similarly try to connect them (briefly), but even if it could to 90°, the 3D information is lost.

That fusing has absolutely nothing to do with Left/Right information, and does not change the fact that when you tilt your head in real life you're now re-aligning what that "horizontal" is and (again IRL) don't lose Left/Right information.

Recap here, (and please take note of this!), that "fusing" will fuse an image to a degree but impart absolutely NO 3D INFORMATION.  Fusing two images together does not mean 3D information has magically shown up.

Guys, I'm unsubscribing from this thread until this circle of misinformation stops.  I lack the temperament for this kind of thing.  Isolated to that alone, I accept that as my failing not any of yours, but for me personally I find it exhausting and I've significantly lost any semblance of a "high road" tone in this, for which I'm sorry.

You are again talking about what you are talking about instead of listening to what others are saying.

Occular torsion is not the vertical movement of the eyeball in it's socket, it's the rolling action of the eye in it's socket.

You really owe it to everyone who you keep calling out misinformation on to actually understand the subject. Again I refer you to the mirror test. See for yourself, your eyeballs roll in their sockets. This is not about move one photo up and down for one eye, this is about tilt your head and watch your eyeball counter rotate.

For someone who is so amazingly frustrated at how others won't just listen to what you are making clear, you are not very good at looking at the information others are putting in front of you.

You would do well to take Airions stance maybe:
Quote:
Originally Posted by Airion View Post

Previously I didn't think it possible that our eyes could rotate in their sockets when we tilt our heads. Now I know it does in fact happen.
.

Edited by Devedander - 10/9/13 at 9:21am
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