Loading ...
Sorry, an error occurred while loading the content.

Re: [PanoToolsNG] The Pupil Goes Back To School ...

Expand Messages
  • Serge Maandag (yahoo)
    ... It s true that with a fisheye the NPP depends of the angle at which light enters the lens surface. I wrote a page about that:
    Message 1 of 8 , Mar 31, 2007
    • 0 Attachment
      > It then adds that theoretically, 'it is impossible to
      > get a perfectly stitched panorama from a fisheye
      > lens.' The proof of this is that PTGui comes up with
      > the 'there may well be misalignments etc' ... when
      > using a 14mm, it is more or less a perfect match.

      It's true that with a fisheye the NPP depends of the angle at which light
      enters the lens surface. I wrote a page about that:
      http://pano.maandag.com/index.php?id=57

      But it shouldn't give you unstitchable results if you are a few mm off the
      NPP.
      Be sure to optimize horizontal and vertical shift though. That usually
      makes a lot of difference.

      And as for the moving NPP: it moves forward and backward. So if you shoot
      in a confined space, it might help to optimize individual FoV for each
      image. Be sure to have lots of control points, though.

      Serge.
    • stuart mcalister
      Serge, Many thanks ... I ll give your paper a read. Regards, Stuart ... ___________________________________________________________ The all-new Yahoo! Mail
      Message 2 of 8 , Mar 31, 2007
      • 0 Attachment
        Serge,

        Many thanks ... I'll give your paper a read.

        Regards,

        Stuart
        --- "Serge Maandag (yahoo)" <yahoo@...> wrote:

        > > It then adds that theoretically, 'it is impossible
        > to
        > > get a perfectly stitched panorama from a fisheye
        > > lens.' The proof of this is that PTGui comes up
        > with
        > > the 'there may well be misalignments etc' ... when
        > > using a 14mm, it is more or less a perfect match.
        >
        > It's true that with a fisheye the NPP depends of the
        > angle at which light
        > enters the lens surface. I wrote a page about that:
        > http://pano.maandag.com/index.php?id=57
        >
        > But it shouldn't give you unstitchable results if
        > you are a few mm off the
        > NPP.
        > Be sure to optimize horizontal and vertical shift
        > though. That usually
        > makes a lot of difference.
        >
        > And as for the moving NPP: it moves forward and
        > backward. So if you shoot
        > in a confined space, it might help to optimize
        > individual FoV for each
        > image. Be sure to have lots of control points,
        > though.
        >
        > Serge.
        >




        ___________________________________________________________
        The all-new Yahoo! Mail goes wherever you go - free your email address from your Internet provider. http://uk.docs.yahoo.com/nowyoucan.html
      • Erik Krause
        ... Usually (as a beginner) one pays far too much attention to the NPP and less or none to other causes of stitching errors. The NPP plays a role *only* if
        Message 3 of 8 , Mar 31, 2007
        • 0 Attachment
          On Saturday, March 31, 2007 at 13:41, Serge Maandag (yahoo) wrote:

          > It's true that with a fisheye the NPP depends of the angle at which light
          > enters the lens surface. I wrote a page about that:
          > http://pano.maandag.com/index.php?id=57
          >
          > But it shouldn't give you unstitchable results if you are a few mm off the
          > NPP. Be sure to optimize horizontal and vertical shift though. That usually
          > makes a lot of difference.

          Usually (as a beginner) one pays far too much attention to the NPP
          and less or none to other causes of stitching errors. The NPP plays a
          role *only* if there are subjects at different distances in the
          overlap region, and they probably are evident only if the distance
          between near and far subjects is relatively large.

          The usual causes of stitching errors are:
          - not allowed to optimze all necessary parameters for a task.
          - wrongly or not calibrated lens
          - too few control points for the amount of parameters to optimize
          (see: http://wiki.panotools.org/Perspective_correction )
          - sideways or up-down displacement of the rotation axis.


          best regards

          --
          Copyright (c) 2007 Erik Krause
          Verbatim copying and distribution strictly forbidden
          except those allowed in wiki.panotools.org/User_Guidelines
        Your message has been successfully submitted and would be delivered to recipients shortly.