Re: Re:Suitability of telescope oculars for stereoscopes

[T3D Peter Homer <P.J.Homer@xxxxxxxxxxxxxxxxx>]

>>Date: Sat, 17 May 1997
>>From: T3D Sam Smith  writes:
>>................
>>Great diagrams John, even I understand this one.  But what always confuses
>>me is the fact that the back of the eye is a curved surface. Has anyone ever
>>done any experiments with photo-sensitizing concave surfaces, such as the
>>inside of half a ping-pong ball? If you photographed a scene in stereo,
>>developed the images using reversal processing to get positives, backlit the
>>images, and viewed them with special contact lenses, would you achieve a
>>more realistic perception? I know the practicality of this all makes it
>>close to impossible, but I'm simply talking theory here. Perhaps it would be
>>more practical if the images were projected onto a special domed screen
>>(sound familiar?)

>>Sam

I have not photosensitized the inside of a ping-pong ball but I once made a
model eye from one by cutting a hole in it and fixing a lens to it .You
could then view from the back the sort of inverted reversed and distorted
image that the brain has to process to get the view of the world that we
are familiar with

                                                                P.J.Homer

>Thanks for asking about this and mentioning the curved surface of the eyes.
>I've wondered about the same thing. I don't have any answer to provide but
>can point to the likelihood that digital imaging could far more easily
>accomplish the recording of an image on a concave surface. It would be easy
>to map such an input to a flat representation. I doubt the phenomenon has
>been explored as one would need the tool to do the exploring.
>
>My hope for such a system is that it might provide a way for the optical
>properties to be relatively free of distortions caused by normal lens
>systems. It might be possible to actually converge two lenses on the
>subject, assuming no background information, and get good stereo results
>without the distortions ordinary optical systems create with converged
>lenses. Just guessing...

Larry Berlin

I have thought along similar lines myself to what extent does the curved
surface of the retina enable the eyes to get away with toing-in without
because it curves around to meet the outer rays unlike the flat surface of
a film. Or is it the brain again that corrects the distortion if the former
it might be a good idea for a stereo camera to guide its flexible film
around a curved path and then use adjustable convergence . Curvature in one
plane only would seem sufficient as the problem with keystoning would only
be horizontal. But wont there be other distortions if this film is then
viewed or projected flat ?. There are some cameras with a curved film path
as have already been mentioned I have seen a a kodak model not the Box
Brownie which used 120 or 127 film.
 The origin of this thread was about the suitabilty or otherwise of
telescope eyepieces for stereoscopes because of the deliberate distortions
built in . This is similar to the discussion a while back about the
suitability of binocular eye lens pairs for the same thing. Would the same
problems arise with binoculars or are they not powerfull enough to have
need of the same deliberate distortion.

                                                                P.J.Homer



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