Re: Converging lenses (was: Window reversal); D|s-TortiO|\|s

[P3D Gabriel Jacob <jacob@xxxxxxxxxxxxxx>]

>When looking at beamsplitter-taken images (with keystoning) in a
>Dr. T'd red-button viewer, there is "no drastic discomfort".  No
>discomfort at all, actually.  So "some keystoning" certainly is
>no problem at all.  At least on the ones I tried.

That is very true, and a little bit of keystoning is not objectionable.
As Dr.T mentioned, convergence is used to keep the window in place
or for long focal length shots. Even in these cases, the keystone
distortion is NOT desirable but is unavoidable, to get the left and
right corresponding images. 

In the beamsplitter, it all depends on other variables such as the
distance, since that will determine the convergence angle. If the
convergence angle is more than a certain small amount, then
keystoning is quite evident and very obvious. Try it and them come
back and tell me if it's a nice effect. If it is, then you certainly
DON'T need a 3D camera to destroy the 3D EFFECT.

>> No, the crux of the discussion was trying out new unconventional ideas,
>
>You don't say how one can have such an idea if artistic reasons are left
>out.  I mean, if you take away that "reason", I can't justify taking
>the picture of a tree!

I'm pretty sure there is alot of ways that would justify taking a picture
of a tree, by using the varied distortions of 3D or 2D cameras, such as
lighting, focal length, etc. without ruining the image. No one is saying
artistic reasons are not justified, but there are a multitude ways of
expressing artistic ideas without assaulting the eyes. I mentioned
hyper, hypo as an example. How about keeping the shutter open and
scanning a pocket laser on someone in the dark. There are people doing
excellent creative work without resorting to cheap distortion faults
to get some perceived new effect.

>If you rule out artistic reasons and rule out technical ones, you
>rule out just about everything -- or is that the challenge?  :-)

No I don't rule out artistic reasons. All I said was it hard to debate,
if someone is doing it for purely artistic reasons. As for technical
ones. I am open minded, if a case can be found where it can be used,
fine. Believe it or not, I think there must be a case that would
justify it, but it's just that none of the open minded people have
suggested any yet. Other than John R.

>P.S. - I still think my keystoned ghost would have worked just fine.

Mike, you seem to have a fixation with ghosts. :-) So I submit one of my
creations from Halloween. Check it out, if you haven't seen it then, at
http://www.generation.net/~jacob/ghost3d.jpg
Anaglyph and no keystoning, of course. Sorry. ;-)

Gabriel



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