Subject: Q: Why do i see inverted Stereograms ?

From: [email-masked] (Jorgen Eriksson)
Date: 18 Aug 92 14:30:24 GMT

This is interesting ! The first time i looked on a stereogram, i think it was
this famous 4 blade propeller, it really stood out from the paper. A few
minutes later i looked at the picture again but now something happened; the 
propeller didn't stand out it now looked like a print of a propeller ! What 
used to be a distant background had become the foreground. Since then, all 
stereograms i have looked on appears 'inverted', even ASCII-stereograms. 
Everyone else i have tried stereograms on seems to view them correctly.
 
Any explanations to this phenomena ?  
 
        Jorgen ([email-masked])
~

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From: [email-masked] (Daniel Green)
Date: 18 Aug 92 19:09:05 GMT

>         Jorgen ([email-masked])

This is simply the difference between viewing cross-eyed verses wall-eyed.
Once you get one eye to look at one image and the other eye the other image,
you must then force the muscles of your eyes to focus them.  This is the
most difficult part of viewing in stereo because your mind "knows" roughly
how far the paper or screen is from your face and doesn't want to try to
focus for some other distance which is needed to fuse the images.

Different people are better at one technique than the other.  I can do both
but find it easier to refocus when viewing wall-eyed.  The disadvantage to
wall-eyed viewing is that the range of angular spread you can learn is much
more limited than you can learn with cross-eyed viewing.  This means that
wall-eyed viewing is only good for small (relative to the viewing distance)
images.

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Daniel Green
[email-masked]
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	 ---|  | D |         --| | D |
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From: [email-masked] (william E Davidsen)
Date: 18 Aug 92 19:29:42 GMT

In article <[email-masked]>, [email-masked] (Jorgen Eriksson) writes:
| This is interesting ! The first time i looked on a stereogram, i think it was
| this famous 4 blade propeller, it really stood out from the paper. A few
| minutes later i looked at the picture again but now something happened; the 
| propeller didn't stand out it now looked like a print of a propeller ! What 
| used to be a distant background had become the foreground. Since then, all 
| stereograms i have looked on appears 'inverted', even ASCII-stereograms. 
| Everyone else i have tried stereograms on seems to view them correctly.
|  
| Any explanations to this phenomena ?  

  The first time you were viewing wide eyed, thereafter you were
crosseyed. Or vice versa.
-- 
bill davidsen, GE Corp. R&D Center; Box 8; Schenectady NY 12345
    I admit that when I was in school I wrote COBOL. But I didn't compile.

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From: [email-masked] (me me me me...)
Date: 27 Aug 92 09:48:21 GMT

How you see the image depends on whether you look at the image cross-eyed
or wall-eyed.  Wall-eyed is the "normal" way, but I know many people who can 
only look cross-eyed.  I worked and worked and can now do either...

[email-masked]