P3D Re: Mirror stereoscopes

["David Lee" <koganlee@xxxxxxxxxxxxx>]

----- Original Message ----- 
From: abram klooswyk <abram.klooswyk@xxxxxx>
To: Multiple recipients of list PHOTO-3D <photo-3d@xxxxxxxxxxxxxxxxx>
Sent: Monday, February 14, 2000 4:09 AM
Subject: P3D Re: Mirror stereoscopes


> David Lee wrote (P3D 3716, 11 Feb 2000, Re: New 3D Site): 
> >(...)
> >I have shown cards with Keystone viewers on stands 
> >(I have 9 of them), but usually I make large (10"x10")
> >prints and use large viewers which I invented and manufacture 
> >for that purpose.
> 
> In an informative article at: 
> http://www.berezin.com/3d/Article.html
> he adds:
> >(...) The principles used in this viewer are not new. 
> >Both aerial stereo viewers and X-ray stereo viewers are 
> >similar in concept. 
> 
> I like the views on the sites David refers to.
> Just as an historical note, the first to have added a second pair 
> of mirrors to the Wheatstone stereoscope seems to have been 
> Hermann [von] Helmholtz, in his Telestereoskop (1857). 
> This was for real-life hyperstereo viewing and had binoculars to it.
> The design for viewing of stereo images (adopted by David Lee)
> was first used by the Frenchman L. Cazes around 1890.
> The X-ray stereo viewers mentioned have been manufactured till
> some thirty years ago, I suppose. They could be used for X-rays 
> up to 14" x 17".
> 
> Abram Klooswyk
> 
Thanks for letting me know.

David Lee