P3D Re: stereo jargon

[abram klooswyk <abram.klooswyk@xxxxxx>]

On 05 Jun 1999 in PHOTO-3D Digest I discussed questions by
Michael Kaplan (PHOTO-3D Digest 3318, 12 May 1999) on "pseudo"
and "anaglyph". Michael also wrote:
>Then there's 'ortho.' I was once asked if I were an 'ortho-man'.

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

Now Tom Hubin writes
(06 Jun 1999, PHOTO-3D Digest 3342):
>Ortho might mean perpendicular or it might be Greek. Although 
>I see several references to a french ortho in the dictionary. 

I'm sorry for not having understood "ortho" was a question too,
I thought it was just criticizing the use of jargon, and I took
the meaning of "ortho" for granted.
Ortho indeed is ancient Greek, what the use of "th" suggests, the
Greek character theta, occurring in many scientific and technical
terms derived from Greek and now used all over the world.
"Ortho" means right (not as opposed to left, but as opposed to
wrong) and also upright. 
("Orthodox"= sticking to the right doctrine.)

"Orthoscopic" is used as opposed to pseudoscopic.

But in stereo "ortho" is mostly used as short for 
"orthostereoscopic", meaning images having "right-looking 
solidity", in which the space-image resembles the original 
closely. 
(This definition was given by W.C. Dalgoutte in a glossary in 
the Bulletin of the British "Stereoscopic Society" in 1967).

An "ortho-man" than is orthodox in stereoscopy, he wants to 
stick to true 3D imaging, will for example not use telelenses 
for images to be viewed with normal focal length lenses.

The definition of orthostereoscopic however allows for size
difference between original and stereo image, when this also
is absent the orthodox terminologist speaks of "tautomorphic"
(again from Greek), "same form", when the form, scale and 
distance of the stereo space image is exactly 1:1 to the 
original.

"Orthostereo seat" is the place in the projection room were
you more or less get an orthostereoscopic 3D image.

(In German stereo literature also a term "orthomorphic" can 
be found, with a somewhat obscure meaning, different from 
"tautomorphic" and "orthostereoscopic")

Abram Klooswyk


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