P3D Re: A simple question (Again)

[Peter Davis <pd@xxxxxxxxxxxxx>]

At 03:23 PM 1/22/99 , you wrote:
>I have asked this before, and I want to see who can explain it.
>
>If you mount a stereo pair with the left eye view on the right, and the
>right eye view on the left, you get a Pseudo Stereoscopic image. However,
>if you mount the image normally, but turn the slide so you are seeing the
>right side with the left eye and the left side with the right eye, all you
>will get is an upside image, not Pseudo.
>
>Take a guess, win a nothing... come on and explain it. I think I know why,
>and Dr T came up with the best answer a few years or so ago (at least I
>think it was him)

This can be illustrated more simply than explaining it in words.  Imagine
you take a stereo photo of two stalagmites in a cave, one behind the other.
 If this is then mounted for parallel viewing, you get something like this:


	 |		|
	||		||
	||		||

In other words, the left eye sees the rear stalagmite to the left of the
forward one, and the right eye sees it to the right of the forward one.

Now turn the picture upside down, and they become stalagtites ... 

	||		||
	||		||
	 |		|

Still, the rear one is to the left of the forward one in the left eye view,
and to the right in the right eye view.  (You spelunkers will have a tough
time mounting slides if you don't remember what the subject was.)

-pd


--------
                             Peter Davis
               Funny stuff at http://world.std.com/~pd
           Resources for children's writers & illustrators:
		  http://world.std.com/~pd/cwrl.html


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