P3D twinning panoramics

[Rod Sage <rsage@xxxxxxxxxxxxxxxxxxxx>]

Sergio wrote:
>I'm tempted to try the same with a much cheaper camera (Horizon) & I
wonder
>how to calculate the stereo base.
>what maximal horintal separation of matching points (linear parallax)
should
>I consider? books recommend 1.2mm for 24x36 and  3mm for 6x6 negs, say
1/30
>of horizontal side or roughly 2° viewing parallax.  In this case should
I
>consider the whole horizontal side or just an "angle of attention"?

The Horizon uses a swinging 28mm lens. So calculate the stereo base as
you would for any 28mm lens. The perspective is the same, only the width
varies. I find a separation of 7-14in. works fine. It is important that
swing lens cameras are parallel to the ground fore and aft as well as
left and right, otherwise the horizon will be concave or convex. So I
base my lens separation on the height of my tripod as well as the
nearest subject. Low tripod 7in..  5ft. tripod 14in., if foreground is
low landscape.
RDS