P3D Re: Slide Mounting Rotational Error Mis-Correction

[michaelk@xxxxxxxxxxx (Michael Kersenbrock)]

> Thanks again for education.  George said (though not in this order) "Any
> rotation (even a small one) will introduce a vertical displacement when the
> displacement is projected in the vertical direction... Vertical
> displacements cannot be fused by the eyes and cause eyestrain... The more
> depth in a stereo pair, the more the horizontal displacements and the more
> of a problem will be a specific rotation."

I also think this "rule" assumes that the camera was a properly aligned
dual-lensed stereo camera.  I've found rotational correction necessary with
dual-SLR's when the thing holding them together was something ... uh.....
less than sturdy and stiff.  In other words the cameras were rotated in
respect to each other... so aligning the chips straight across effectively
causes rotational error.  Makes my slow mounting even slower.  :-(

BTW... this is the result of my very very inexpensive dual Pentax 
(spotmatic generation) SLR experimentation.  There are some bugs to be
worked out, and one of them is this rotation that varies from image to
image.  My little $1 flash-bar sort of thing that holds them together
is utterly inadequate.  I'll probably have to actually build something. :-)

Mike K.


> 
> Michael Georgoff
> San Jose, CA


------------------------------