P3D 3D Fallacies

[Dale Walsh <dwalsh1@xxxxxxxxxxxxxxxx>]

abram klooswyk wrote:

> Dale Walsh wrote (P3d 3358, 19 Jun 1999):
> >As an unrelated question, has anyone any sources of
> >information on the 16th century Florentine painter
> >Jacopo Chimenti who did stereoscopic drawings?
>
> The short answer is: he didn't.
>
> Longer:
> When talking about Sir David Brewster, never forget that he
> did numerous stereoscopic inventions and that he brought
> stereophotography to France and to the Crystal Palace,
> starting the great public interest in stereoscopy.
> However, on the other hand he is the source of several more
> or less serious errors and fallacies in (the history of)
> stereoscopy, a notorious one being the Chimenti "stereoscopic
> drawings".
> A detailed discussion of this fallacy is in:
>      Nicolas J. Wade: "Brewster and Wheatstone on Vision",
>      Academic Press, London, New York etc. 1983.
> This book contains almost everything which both scientists
> wrote on binocular vision and stereoscopy (except Brewster's
> book "On the Stereoscope"), with a critical assessment by Wade,
> who is an authority on the subject.
>
> On the Chimenti drawings it deals on page 46-49 and 183-192.
> In short, Chimenti made a drawing of a man from two slightly
> different viewpoints (and on a slightly different scale).
> The small differences give rise to accidental local depth effects,
> when you fuse the pair binocularly.
> Brewster however said that the stereo effects were intentionally,
> which challenged Charles Wheatstone's priority. The debate rose
> high, but was already settled in the 19th century.
>
> The great von Helmholtz said: ... it seems to me very unlikely
> that Chimenti intended them [the drawings] for a stereoscopic
> experiment, because the stool, the dividers, and the plumb line,
> which could easily have been drawn correctly, are treated as
> unessentials and all drawn so irregularly and so differently that
> they cannot be combined [stereoscopically]. (...)
> It seems more probable to me that the artist was not satisfied
> with the first figure and did it over again (...).  (1866).
>
> Brewster's fallacy has been repeated over and over again, till
> now, on P3D....

Thank you for including the sources of your information on Chimenti.  I would have
to agree with you based on this information.  Sorry for continuing the fallacy.

> In PHOTO-3D Digest 3032, 20 Oct 1998, in a posting called
> "From Euclid to Wheatstone and further on", I have argued that:
> "The stereoscope could not have been invented before the
> stethoscope." (The latter was invented in 1812).
> In PHOTO-3D Digest 3035 I have added: (...) "making two
> perspective projections and fusing them was not *conceivable*
> before the 18th century."
>
> By the way, Dale Wash has an interesting site with many stereo-
> images (http://welcome.to/solidillusions),

Thanks.

> but it features
> another of Brewster's fallacies:
> "The principles behind stereoscopic imagery were developed by
> Euclid in ancient Greece."

> I have discussed Euclid's "binocular" theorems in TECH-3D

> Digests 366 and 367, 26 Sep 1998, in postings on "From Euclidto Wheatstone".
> Euclid didn't say anything on depth perception or stereoscopic imaging.

I have seen this repeated many times and I am hesitant to accept this as a
fallacy.  Do you have any sources for this assertion?  I have seen it written
numerous times including the statement in Hal Morgan and Dan Symmes Amazing 3D book
which says that Euclid laid out the principles of binocular vision.

Considering another potential fallacy, I just saw Encounter in the Third Dimension,
which I found highly enjoyable.  However they say that the pioneers of Cinema, the
Lumiere Brothers, shot their first film using two cameras for 3D.  The famous
sequence of the train coming into the station.  Was this shot in 3D?  I had never
heard that before.

>

Dale Walsh
mailto:dwalsh1@xxxxxxxxxxxxxxxx
http://welcome.to/solidillusions

http://zap.to/thegangesin3d



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