On Tue, 15 Sep 1998 15:53:29 +0200, Helmut Dersch wrote:
>Neuman-Ruether wrote:

>> >Seems we have to agree to not agree on that subject.

>> I guess so... (and it seems so really simple to me...;-).

>At least this discussion forced me to rethink several of my points,
>which I am now more convinced of than before...sorry ;-)

Me, too, and, me, too, and, me, too...;-)

>I have generated a couple of example images in various projections
>(the same 135degree-view as 16mm-fisheye, 7.5mm-rectilinear, and
>16mm-panoramic image) and posted it together with a few (biased)
>summary remarks:
>

The above is really excellent, and I think, very objectively
done. And, I still find it odd, with apparent complete agreement
between us on the technicalities, basics, process, seeing-
characteristics, image-qualities, and all else, as far as I
can tell (you even seem to agree with me now [which you did not
appear to do with your first post...;-] that we do see in
curves, and further, that "small objects look more natural in
the fisheye image..." [I would have said "rounded objects"
rather than small - though, I guess, as I think about it,
even straight-sided objects look OK if small in a fisheye image,
so maybe your choice of words is the better one...;-], that we
don't come to the same (rather obviously necessary, as it
seems to me, given what goes before the conclusion...;-)
conclusion about the preferable imaging-perspective type
for representing what we see in a wide field of view on a
small imaging surface...! ;-) I would ordinarily attribute
this to "learning" and prejudice about the "rightness" of
the two- or three-point rectangular-perspective viewing systems
(it is the one [technically, though often not actually, if
one checks closely enough...;-] which is used in virtually all
of the images we encounter), but you have so thoroughly shown
that this is not one of your limitations...! ;-)
BTW, it occurred to me after an e-mail from someone who could
not accept the curvature of our sight as being similar to that
in the fisheye image, that maybe people think of fisheye images
as being necessarily like those commonly published that are taken
at unnaturally short distances from subjects, and which show a
rather extreme field of view... (silly-image type fisheye photos).
In the full-frame 16mm view on your web page at:
http://www.fh-furtwangen.de/~dersch/perspective/Wide_Angle_Perspective.html
if people would imagine the image with approximately the top
third and bottom 1/4 removed, the sides rounded, the edges softened
and blended to black, and the area away from the extreme center
softened in focus, it may look rather familiar as an image type...;-)
Restoring the image to the form in which it appears on your web
page is not an unreasonable thing to do for the sake of producing a
small image for viewing, I think, and does not destroy its essential
value as a way of representing the way we see...
If both image types keep the horizon line centered, the swing-lens
panoramic image has a lot to commend it also, but if the horizon
line is moved much away from center, I think the fisheye works
better as a small-image normal-distance-viewed wide-angle
representation of what we see.
Thanks for putting up that web page, and thanks, again, for a
most interesting discussion! (Which has caused me to refine my
thinking on the subject, also...;-)