Re: Stereo Difficulty (McKay)

[P3D Dr. George A. Themelis <fj834@xxxxxxxxxxxxxxxxxxxxx>]

Paul Talbot writes:

>Herbert McKay has some interesting comments on the topic.  He writes:
>"Stereoscopic perception is a characteristic of marked variability...

The Giant has spoken... (McKay is my idol...)

>Some people have such a marked stereoscopic sense that they are always
>painfully aware of the flatness of the ordinary photograph; 

While I don't mind seeing flat prints (I am used to them, I guess...) if
you mount a flat pair in a slide viewer, I am painfully aware that the
pictures are flat (maybe because I am used to seeing depth through this
viewer?)  I can detect flat or pseudo mounted pairs right away, something
that many people cannot do.  Does that mean that I have well developed
stereoscopic perception?

>there are
>others [who rely on non-stereoscopic clues to such an extent that they]
>see depth in a good planar photograph...Such people see nothing unusual
>when viewing their first stereogram...

Yes!  I've met a few of those people.  What a turn off!  You expose them to
their first stereo image and instead of saying "WOOOOWWWW!  This is
GRRRREEEAT!" they just ask you "what is this?  where was this taken?  what
am I looking at?" (or something stupid like that... :-))

>McKay also reports that the consensus of eye professionals surveyed
>was that: "about 1/3 of all adults have low stereoscopic perception,
>and of the remaining 2/3, from 12 to 15 percent have fully developed
>stereopsis."  

I wonder how those eye professionals measure the degree of stereoscopic
perception.  I have a stereo pair that I use for testing stereopsis.  I
have noticed that some people (like my wife, for example) take long to read
the hidden message (which jumps right away for me).  I was thinking that
there might be a correlation between the time it takes the observer to see
the image and the degree of stereoscopic perception, but I am not sure.

>Also, "those who practice stereoscopic photography are
>usually in the high bracket..."

I can buy that...

>It may be a good idea to think of stereoscopic perception as a
>continuum, rather than a clearly defined "yes" or "no."
>Paul Talbot

YES, Paul.  The answer is a definite YES.  Thanks for the input!

George Themelis


------------------------------

End of PHOTO-3D Digest 2237
***************************
***************************
 Trouble? Send e-mail to 
 wier@xxxxxxxxxxxxxxxxxxxxxxxx 
 To unsubscribe select one of the following,
 place it in the BODY of a message and send it to:
 listserv@xxxxxxxxxxxxxxxxxxxxxxxx 
   unsubscribe photo-3d
   unsubscribe sell-3d
   unsubscribe overland-trails
   unsubscribe icom
 ***************************