wwp@yahoogroups.com:
Re: Twenty Questions for the VR Photographer
Erik Krause 2005-Sep-15 11:18:00
Am Wednesday, September 14, 2005 um 14:58 schrieb Scott Highton:
> The Focal Encyclopedia of Photography includes the following regarding
> nodal points and planes:
>
> "Rotating a lens about a vertical axis through the rear nodal point
> keeps the image of a distant object stationary
[...]
> "Focal length and image conjugate distances are measured from the rear
> nodal point, and object distances are measured to the front nodal
> point."
They are simply wrong (a typo I suppose) as you can see if you think
about the above statements: The rear nodal points distance from the
film or sensor is exactly the focal length. This would be far inside
the camera for a 8mm fisheye. The real "no parallax" point is very
near to the front lens...
The axis however can be vertical, horizontal or whatever. It's a
point, and as long as you rotate around that point there will be no
parallax - at least for a rectilinear lens since for a fisheye the
nodal point changes with the angle of view.
best regards
--
Erik Krause
Offenburger Str. 33
79108 Freiburg