Re: [photo-3d] Beam splitters vs. Image splitters

[Peter Davis <pd@xxxxxxxxxxxxx>]

Ok, suppose you have your cameras like this:


      \      __[ ]
       \    [__  |
        \      [ ]
       _
     _| |_
    [_____]


They would have the same view, right?  Now move one of the cameras to the 
left or right ... voila! Binocular disparity.  (Apologies for the crummy 
ASCII art.)

-pd


At 05:57 PM 01/09/2001, you wrote:
>Okay, I'm confused now.  How do you get a stereo pair with a beam
>splitter and two cameras at right angles to each other.   I understand
>how the "image splitter" works in that it has a left side and a right
>side which are exposed on the negative.  However a single "beam" of
>light, split in two provides the same image on both negatives.  Where is
>the horizontal disparity with a beam splitting device?
>
>Where did I get lost in this?
>
>Ron
>
>pd@xxxxxxxxxxxxx wrote:
> >
> > ----- Original Message -----
> > From: "Bryan Mumford" <bryan@xxxxxxxxxxxx>
> > To: <photo-3d@xxxxxxxxxxx>
> > Sent: Tuesday, January 09, 2001 12:41 PM
> > Subject: [photo-3d] Beam splitters vs. Image splitters
> >
> > > If you are willing to educate me further, I'm curious why beam
> > > splitters are used in photography. Why do you wish to capture the
> > > same scene on two cameras?
> >
> > The same could be said of stereo photography in general:  Why 
> photograph the
> > same scene twice?  The fact is that with two cameras at nearly right 
> angles,
> > and a suitably placed beamsplitter mirror, you can get stereo pairs, 
> and you
> > can vary the spacing and "toe" in ways that the sizes of the camera bodies
> > would not allow with normal twin rigs.
> >
> > -pd

--------
                                 Peter Davis
                  Funny stuff at http://www.pfdstudio.com
                  "The artwork formerly shown as prints."