Originally Posted by Airion
"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.
It was exaggerated as I was trying to make the point visible while drawing with ms paint on a trackpad.
That said the point is your eyes are not attached rigidly to your skull like the two cameras would be that are used to take stereo imaging and vertical parallax is something that is introduced on a regular basis of every day viewing. We do not always see in perfect left right parallax only.
I think I really need to just crank out the test images because all this theoretical debate gets us nowhere and not even fast. I am perfect ready to accept that I cannot actually perceive depth from vertical parallax alone however all my experiences watching 3D movies up until this point (some of them indeed lying down) makes me really need to see the test done right to believe it. Because I am absolutely sure I could feel the depth difference with my eyes of foreground objects in hugo while lying on my side.
I think what a lot of people are missing out on is that I am not making a simple argument from A to D, I am doing A to B to C to D.
That's why tgm keeps thinking what I bring up is a red hearing... I think he thinks it's my argument, it's not, it's a supporting argument for the direction I am going.
Basically what I am saying is Thesis: You are able to extrapolate real depth information from purely vertical parallax image data.
A: Your eyes naturally function outside of pure left/right parallax (this is the whole point of bringing eyeball roll into the conversation, it's not a red hearing, but the first step in proving you normally deal with vertical parallax)
B: Essentially your brain is not a computer chip that can only do one thing and in only one way when it comes to depth perception
C: Once we accept that pure left right parallax is not absolutely necessary to get depth information from stereo pair images we can explore whether it's really possible or not on purely vertical parallax.
Again this is all really silly as I pointed out earlier, a test pattern can pretty quickly reveal whether or not you can determine depth from vertical parallax in a horizontal offset or not .
Until then I am many others can attest to the (claimed) perception of depth while watching entire movies lying down (without notable eye strain I may add) and you and many others may continue to tell us how that is not possible.
Thank you for at least being open enough to research the idea I put forth (eyeball roll) instead of just figuring out how to explain to me it's wrong before even understanding the idea yourself. If others were so inclined this might not have stretched into quite the long explanation of such a simple point as it has... most of page three is trying to convince tgm that your eyes roll in their sockets while he tries to convince me about something else entirely.
I am totally open to the possibility that all the depth I perceive while lying down watching 3D is purely occlusion, contrast, brightness etc based and not stereo based, I just would like to test it in a way that is not subjective nor based on expectations of how other things we do relate or support this function.,