Re: Effect of Eye Position on Perception

[P3D Gabriel Jacob <jacob@xxxxxxxxxxxxxx>]

I wasn't going to comment on this but since John Roberts posted his thoughts
on it, I thought I would chime in. 

John Roberts writes

>I think something's seriously wrong here - in the wording of the article that
>Ron quoted, or in the author's understanding of vision research, or in the
>last few centuries of vision research as described by the article. What it
>sounds like the article is claiming is that researchers have always believed
>that eye position has nothing to do with perception of spatial relations.

I would have to agree with John on this one. When I read the article posted
to P3D it mirrored my sentiments exactly. I thought to myself, "Are they
serious?". Where have they been the last few hundred years. I had trouble
following it, and it didn't make much sense either, let alone hold up.

Most of what they claim about conventional wisdom being wrong is in error
because that is "their" conventional wisdom. If they bothered to research
the topic properly they would have found out that it's not conventional
wisdom. 

Quote from "researchers" 
>In two reports in the British journal Nature Wednesday, researchers  
>from the Istituto di Neurofisiologia del CNR in Pisa and the Universita 
>di Roma ``La Sapienza'' in Rome and the University of California, Los 
>Angeles, say there's a lot more to seeing things than meets the eye. 

Now really is this not known!!! It is known (and this is the bare basics)
that the brain has a big if not bigger part in visual perception, so yes
there is more to seeing things than meets the eye. Not new revelations
here.

Again from the "researcher" or so they claim ;-)
>David Burr of the Pisa center says, ``Conventional wisdom has it that  
>the perceived spatial relationship between visual stimuli depends on 
>retinal information alone -- and does not require any extra information 
>about eye position or the direction of the gaze. Conventional wisdom is 
>wrong.''

Here is another example of their supposed conventional wisdom. As 
Ron Doerfler correctly mentions, "people unconsciously tilt a viewer up
or down to mimc the viewpoint of the camera when the picture was taken".
This is a very well known effect among 3D enthusiasts. I would think
serious researchers would know about this also.

Another quote from "researchers"
>It also depends on the direction of the gaze. To ensure that the  
>visual world remains stable as we look around us, in addition to the 
>retinal image, the brain must also take into account the movements of 
>the eyes and head.
John R. replies
>There are also problems with the non-3D aspects. When I shift my eyes or
>head to the side, I don't think the whole universe has suddenly moved.

That is a perfect example of a perfectly known effect. This is no "new
discovery" and visual researchers know very well that in normal visual
perception, the universe doesn't move when shifting eyes or head. But
rather if the focal length is increased so that it is telephoto (similiar
to viewing the world with low power binoculars) the world will indeed
seem to move. But this is not a new discovery and is well known. Heck
I even know about it and I'm no visual reseacher. Only an amateur.
So John is right that the world doesn't seem to move and is probably
intertwined with the brains wiring to take into account the eyes movement.
But this seems to go haywire when viewed with binocular vision.

Gabriel who really gets ticked off by so-called experts and bad commercial
3D! ;;;-) AND is not having a bad day. Thank-You. :-)

P.S. If the paper added insight to the effects they were describing this
wouldn't be so bad, but claiming they refute supposed conventional wisdom
is what was irresponsible.


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