P3D Re: stereo jargon

[abram klooswyk <abram.klooswyk@xxxxxx>]

Michael Kaplan wrote (PHOTO-3D Digest 3318, 12 May 1999):
>I've never thought 'pseudo' was a very good term for accurately
>describing the phenomenon resulting from reversed film chips or 
>prints, which could be more accurately described as 'inverse' 
>or 'reverse' - a scientist could surely come up with a better term. 
>There also are effects (like conversion of 2-D to 3-D) that might 
>clearly qualify as 'pseudo' or false or fake.

I've never thought 'stereo' (=solid) was a very good term for 
accurately describing the phenomenon resulting from 3D imaging of 
*soft* bodies (I think of course on marshmallows, fungus and octopus).
A scientist could surely come up with a better term.(:-))

The problem is that 'stereo' and 'pseudo' both *were* coined by a
scientist, in the form of "Stereoscope" and "Pseudoscope".

Charles Wheatstone, since 1834 professor of Experimental Physics 
at Kings College, London, said on June 21th 1838 to the members
of the Royal Society: "(...) The frequent reference I shall have
occasion to make to this instrument, will render it convenient to
give it a specific name, I therefore propose that it be called a
Stereoscope, to indicate its property of representing solid figures."

In the same reading Wheatstone said:
"A very singular effect is produced when the drawing originally 
intended to be seen by the right eye is placed at the left hand 
side of the stereoscope, and that designed to be seen by the
left eye is placed on its right hand side." (....)
"... this, which I shall call its *converse* [italics] figure."
In a second reading, held in 1852, Wheatstone elaborates on 
"those phenomena which I have termed Conversions of Relief".

So "converse" should be the term. But then he took an action
which overthrew this again, by demonstrating an instrument 
which:
 "(...) conveys to the mind false perceptions of all external 
objects, I have called it the Pseudoscope."

It consisted of two rectangular prisms mounted with the largest
surfaces towards each other. 
Wheatstones readings were published in the Transactions of 
the Royal Society of London. The first booklet on the subject
(only 16 pages) was in French, by the abbé Moigno, a little gem 
called: "Stéréoscope, ses effets merveilleux, Pseudoscope, 
ses effets étrangers" (Paris, 1852, 16 pp)

In short, the terms stereo(scope) and pseudo(scope) are sacred
by scientific origin and clerical approval, whether you like
it or not :-)

Michael Kaplan:
>Similarly, I've never thought 'anaglyph' was an appropriately
>descriptive term for two-color viewing. Couldn't it be 'two-color' or
>'red/green' or 'red/cyan'?

Greg Wageman (same digest and date):
>I'd love to know the etymology of that term with respect 
>to stereography.

Greek ana=up, glyphein=cut out. Anaglyph was originally an art term to
describe sculpted reliefs. In the Hellenistic time (my encyclopedia 
says) the different colored layers of some kinds of stones, like
onyx, were used to get the effect of polychromy (more than one
color). The superposition of two complementary colors for viewing 
of stereopairs, as invented in the late 19th century, obviously 
reminded of the basso-relievo's (low reliefs) in different colors.

And "ortho"? It just means "right", if I'm right :-). 

Abram Klooswyk


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