[photo-3d] Re: beamsplitters

[Olivier Cahen <o_cahen@xxxxxxxxxxxxxxxx>]

    In your actually crappy discussions on the meaning of the word
"beamsplitters", none of you even tried to refer to the document which now is the
reference, the "Glossary of Terms Used in Stereoscopy", published by Don Wratten
in the September 2000 issue of  "Stereoscopy".
    The glossary gives the two current definitions of the word (as a light flow
splitter and as an image divider), but it states that the second definition is
colloquial and that the term "image splitter" is more appropriate.
    Of course, that is crappy is the misuse of an image splitter, such as trying
to show in projection some stereo images produced by a Pentax or similar. The
device is not crappy for people only viewing the images in a stereoscope.

>    Date: Tue, 09 Jan 2001 02:12:21 -0800
>    From: Mike Kersenbrock <michaelk@xxxxxxxxxxxx>
> Subject: Re: Are beamsplitters crappy?
> Bryan Mumford wrote:
> > Would  others agree that beam-split pairs are unsatisfactory?
> Depends upon what one is using them for.  While I don't agree that
> they are crappy, I do agree that they have significant restrictions
> in their use, or at least my Pentax one does.
> > about it this way before, but I'm getting four times as much picture
> > data in two full frame cha-chas than I would get in a single frame split
> image. Maybe a beamsplitter is not a worthwhile project after all.
> In terms of amount of film you get exposed, quite true. But a
> "beamsplitter" (image splitter) can take the two images at
> the same time (and with perhaps a 1/4000 sec shutter if light is
> bright enough) -- something a cha-cha has no hope of achieving.
> "Beamsplitter" also probably would provide better rotational
> alignment between the two images (one thing I certainly never
> seemed to be able to do too well when cha-cha'ing with my wife's
> digital camera).  :-)
> I'd call it a step up from cha-cha's, but most any stereo camera would
> be a step up from the beamsplitter (except only for some special niche
> circumstances).
> Mike K.
> P.S. - When I was married mumble years ago, I had a friend use my Pentax
>        stereo adapter, and his photos are loved by us more than the ones done
>        by the professional (and not just because it was 3D, the image content
>        was important too :-).
> > Bryan Mumford
> > Santa Barbara, California
> > http://www.bmumford.com