Re: PHOTO-3D digest 1359

[P3D Neil Harrington <nharrington@xxxxxxxxxxxxx>]

William Carter writes:

>Let me repeat a part of my posting. I thought it clearly established=20
>that Cherubin had made a stereo microscope:
>
>Single-Lens Stereoscopic Methodologies.
>Dual Optical Paths.
>
>The first application of a single lens stereo system has been tried as=20
>early as 1677, by a French philosopher - le Pere Cherubin, of Orleans -=20
>a Capuchin friar. And this, fewer than twelve years after the first book=20
>on microscopy, Robert Hooke=92s Micrographia (1665). The following is an=20
>extract from the description given by Cherubin of his instrument:
>
>=91Some years ago I resolved to effect what I had long before=20
>premeditated, to make a microscope to see the smallest objects with the=20
>two eyes conjointly: and this project has succeeded even beyond my=20
>expectation; with the advantages above the single instrument so=20
>extraordinary and so surprising, that every intelligent person to whom I=20
>have shown the effect has assured me that inquiring philosophers will be=20
>highly pleased with the communication.=92[1], [2]
>1. Cherubin. La Vision parfaite, 1677
>2. Translation by; J. Hogg.  The Microscope: It=92s History, Construction=
>,=20
>and Applications, p. 113, 1854
>
>In this, Cherubin establishes both intent to produce a stereo view, and=20
>the un-expected result of having such a view.

William, I think you may be reading something into that that just isn't
really there.  The phrase "to see . . . with the two eyes conjointly" does
not suggest to me that the writer understood anything about stereopsis, or
that achieving a 3-D view was any part of his intent.

Field glasses and opera glasses have been made for well over a century to
allow the user "to see with the two eyes conjointly."  I've never heard it
suggested that these designs had anything to do with 3-D perception, and I
doubt that they did.  It is simply more comfortable and more satisfying
generally to be able to use an optical instrument with both eyes at the same
time, and it isn't surprising that the same idea should occur to a designer
of microscopes sooner or later.

In the passage you've quoted, Cherubin says that his instrument has
"advantages above the single instrument so extraordinary and so surprising,
[etc.]," but doesn't actually say or hint what those advantages are.  It is
certainly possible that he saw a 3-D effect and was impressed by it without
understanding it, and in the absence of his mentioning anything about depth
or solidity I would suspect that to be the case.



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