[MF3D.FORUM:797] Re: I need a MF 3D Dr.

["Dr. George A. Themelis" <DrT-3d@xxxxxxx>]

>Drawing on an example I
>was given, let's say the closest object in a scene is a coin
>standing on edge, thin edge toward the camera.  Say the physical
>depth in the scene is not very great, and the scene is fairly
>close.  The MAOFD formula may yield a stereo base that is
>significantly larger than 1/30 the distance to the near object.
>It is possible that the left camera will see the "heads" side of
>the coin, while the right camera sees the "tails" side.  When
>you go to view the two images in 3D, there will be problems,
>even though the MAOFD has not been exceeded!

Two comments on this:  The coin that stands on its thin
edge toward the camera is not a particularly good example
of a subject with limitted depth, especially if photographed
in a close up. Standing on its face would be a better example
but then it does not have the problem you described.  The other
comment is that when our eyes look at the coin on its side,
we do not seem to be bothered by the fact that the left eye
sees quite a bit of the left side and the right eye
sees quite a bit of the right side.

>Extending the example to more likely real situations, it is
>easy to see that if the base is so large as to see different
>sides of a near object, fusing the two chips into a pleasing
>3D image could be quite difficult or impossible.

I would think that the stereo base would have too be way
too large for this to be a problem in a practical situation
and you will first ran into other problems (like insufficient
overlap between R and L).

>From DrDave's posting it seems that mounting was the problem
here.  Our club's newsletter had a nice write up on the stereo
window.  I will send Bill a copy.  I think it will clarify
a few things about mounting and the stereo window.  Also,
in NSA DrDave will demonstrate mounting of stereo slides.
Perhaps DrDave or Paul can include MF mounting as an example?

George