Re: colored vignetting

[P3D Allan Woods <allanwx@xxxxxxxxxx>]

I responded:

>>I am at a loss to understand here...
>>If you want to eliminate the colored vignetting, remove the filtres.
>>
>>The colored vignetting IS the 3-D information in the particular
>>system you are trying to make.

Paul Kline replied:

>The principle that makes anaglyphic SL3D work is to overlay a blueless
>image from the left perspective with a redless image from the right
>perspective on the film, then reconstruct them with red-blue glasses.

I go on (and on...)

Let me try to explain what I understand of this method... then maybe
you can correct where I differ from your understanding.

The red-blue filtres are placed at the theoretical aperture of the
lense.  The light paths of "in-focus" objects then pass through
the filters and intersect "exactly" at the filter plane, thus not
getting any colouring from the filtres.

Objects which are "out of focus" will have light paths which intersect
either in front of or behind the filter plane.  The result is that
the light paths will pick up some colouring, left and right, on their
way to the film plane.  Because of the geometry involved, objects
in the foreground will be tinted left-right while objects in the
background will be tinted right-left.

When viewed with anaglyphic glasses, these images "appear" to be
shifted left or right because the complimentary fringe colour is
occluded by the filtre in front of each eye.

Thus we have what appears as "parallax" and gives the depth illusion
contained in the "out of focus" elements.

Objects without the colour fringing do not apear to be "shifted" and
therefore will appear to be at the "window plane."

Remove the fringing and eliminate the 3-D effect, n'cest pas?

I don't believe this system has anything to do with the notion that
each red or blue portion of the image is formed by a "sub-lense"
located at the centroid of each half of the aperture - particulary
since the "distance between centroids" and using that as the basis
for the calculation of a "stereo base" is irrlevant and does not
apply in this case.

"Stereo base" has no place here.  It applies to 2-lense systems.


>This is not vignetting (it is also not accurate to state that "the depth
>information is encoded in the red-blue fringes of out-of-focus areas"
>as someone else has done).
>

We differ here, and I would like to know why.

>Vignetting occurs because the apertures for the two images are not
>centered on the lens axis, causing the picture to be overly red on
>the left and blue on the right.

Here is one point where our ideas seem to be different.  The "dual
aperture in a single lense" paradigm in not the model which pertains.

We are not dealing with two pictures!  It is a single image with the
depth information contained in the coloured fringes of the "out of
focus" objects.

What is needed is a paradigm shift.
Two seperate images are not the only way to create the 3-D illusion.
Please consult the original patent text for confirmation.

allanwx@xxxxxxxxxx


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