[photo-3d] Re: again those figures!!!

["Oleg Vorobyoff" <olegv@xxxxxxxxxxxxx>]

Thank you Sergio Baldissara and Abram Klooswyk for your detailed
explanations.  I understand now that 2° convergence is a recommended (but
not absolute) maximum for viewing stereo pairs, especially under projection.
I still do not understand why greater convergence is difficult to view,
considering that we routinely look at things with 12° convergence and more,
for example, while reading.  My guess is that since a normal photograph is
actually a rectilinearized projection it does not recreate precisely enough
the curvature of objects viewed with a lot of parallax.  If that is true,
perhaps the center portion of a fisheye image, enlarged to fill the frame,
could be comfortably viewed despite greater than recommended convergence.
Has anyone actually tried that?

Oleg Vorobyoff

My original question:
>...Is there some definite physical or physiological
>basis for the 2° maximum, or is that just a guideline?
>After all, most of us can easily fuse the printing in a
>book a foot away - that is a full 12° of crosseyedness.