[MF3D.FORUM:397] Re: fl/30

["Bill Glickman" <bglick@xxxxxxxx>]

John B

      What happens when the camera lens fl does not match the viewer fl.
For example, camera lens is 150mm and the viewer lens is a constant 78mm?
Now what do I use for the deviation figure in your formula?

Thanks
Bill


----- Original Message -----
From: <Tloc54452@xxxxxxx>
To: Medium Format 3D Photography <MF3D.Forum@xxxxxxxxxxxxx>
Sent: Tuesday, April 04, 2000 5:23 PM
Subject: [MF3D.FORUM:396] Re: fl/30


> >      Sorry I did not properly quantify my question... I meant this...
> >if you only view MF stereo pairs in a viewer, no projection, then using
your
> >formula, should I keep the deviation constant?  If so, should it be 2.7?
>
> If your lenses, in camera and viewer, are 80 mm, the max OFD should be
> 80/30 = 2.7 mm.  That's a general number that people like Bob Mannle use
> for all purposes, regardless of focal length.  I don't know if that's wise
or
> not.  It seems to work well enough to satisfy many people.  Realize that
> this is a maximum OFD.  Nobody says you must go this high for every shot.
>
> Personally, I don't do it this way.  My regular slide bars have 67 mm of
> travel to match my IPD.  My camera and viewer lenses are 80 mm.  So I
> get the ortho view every time.  This means height, width, and depth
> have the same proportions in the reconstructed image and also the scale
> of the reconstructed image is the same as that of the original.
Personally,
> I think it's the onliest way to go.  8-)
>
> There was a long discussion on P3D years ago about whether or not
> everyone can see stereo errors (non-orthoscopy).  I don't know, but
> many people can.
>
> John B
>