[photo-3d] Re Zeiss OO Viewer

[Peter Homer <P.J.Homer@xxxxxxxxxxxxx>]

Ralph Johnston/ Lindsa Aherman wrote

>Can someone please explain the difference between "one-ring" and
>"two-ring".  What ring are they referring to?  Does one type of viewer
>reverse the images and the other not?  Would this viewer work with my
>Franka beam splitter?  I think I saw a description of this viewer in a book
>somewhere, but can't remember where.
>
>Stereo OO Zeiss Ikon Viewer - Beautiful
>                                                       Item #452168481
>
>Go to search -by item # to view this e-bay item.
>
>Thanks -Ralph
>
>
>>Zeiss Ikon OO Stereo Slide Viewer
>>
>>     A beautifully designed cream and black bakelite internally lighted
>stereo slide viewer for stereo images on a 2" x 2" single slide mount.
>Operates on two
>>     D cell batteries and can accomodate the special halogen bulb for
>twice the brightness.
>>
>>     Designed for OO "two ring" type stereo slides. [35mm slides made with
>a beamsplitter attachment - that which use a single common lens (Stereo-Tach,
>>     Pentax, Stitz, Contina & Contaflex with Steritars, etc) need a O "one
>ring" type viewer]   -  [35mm slide stereo pairs made by two separate lenses (
>>     Ultra close up Realist, half frame, Nimslo, Nishika, Image Tech,
>Contax with Stereotars, etc.) need this OO "two ring" type viewer].
>>
>>     Viewer is in like new condition, with photo copy of instructions in
>English

I am not actualy familiar with this viewer but I suspect the single ring O
refers to the single lens of an ordinary camera to which a beamsplitter can
be fixed to produce stereo pairs. The single lens transpose the two images
so the viewer for these does not have to do so. The two ring OO seems to
refer to conventional stereo cameras with two lenses but with a short base
for macro so that the two half frame pairs making up each 35mm frame need a
transposing viewer. So your Franka splitter would need the single ring O
non transposing viewer.   P.J.Homer