free viewing

[P3D Gabriel Jacob <jacob@xxxxxxxxxxxxxx>]

Gregory J. Wageman writes

>Then how do you explain the ridiculous popularity of those random-dot
>stereogram books?  Seeing those images requires a facility very similar,
>if not identical, to freeviewing stereo pairs.

Yes the mechanics of viewing random-dot-stereograms is identical to 
freeviewing stereo pairs, the problem thou is that it would be 
harder for the average person to free view a stereo pair because
the separation between the two views is usually 3.5 inches, but
in RDS they are usually 1.5 inches(in posters) and much less in
the books which makes it much easier to fuse.
Anyways that's my 2 cents.
By the way here it is, in anaglyph format, at

http://generation.net/~jacob/my2cents.jpg

Gabriel

Note: I know this is a bit late but listserv was not accepting
my posts yesterday.



Larry Berlin writes

>I think you are right, Greg. The only problem is that many who finally were
>able to see stereograms don't know that what they were doing is the same
>thing as free-viewing stereo pairs. A bit of additional education will cure
>that but not the large number of people who still can't see stereograms or
>who find the process difficult. For that group, a good viewer is still needed. 
>
>Stereograms were relatively unfriendly in that they didn't provide viewers
>for those who couldn't figure out the method. That's one critical weakness
>in the marketing of stereograms that could have been but never was fixed.
>(The inexpensive devices exist but weren't accepted by the publishers who
>figured they didn't need it... it's their loss.)

A very easy and inexpensive viewer for helping one to "freeview", which
I have never seen anyone mention, is reading glasses. I personally 
don't wear glasses but I bought a pair, which can be usually had
at drug stores or flea markets without a prescription for under $5.
With a pair of reading glasses it is much easier to freeview RDS 
up to poster size to books with the added advantage that the RDS
are magnified! It also helps for freeviewing stereo pairs.
(One might argue thou that strictly speaking using reading glasses
is not freeviewing but what about people that wear glasses, they
are considered freeviewing even thou they are wearing glasses.)

Gabriel
jacob@xxxxxxxxxxxxxx

  


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