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Weird black haze when shooting without Zenith and Nadir shots

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  • Jeremy
    Hi Everyone, I ve been experimenting with making my panoramas without taking Zenith or Nadir shots. I usually don t have time to manually add control points
    Message 1 of 10 , Oct 25, 2007
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      Hi Everyone,

      I've been experimenting with making my panoramas without taking Zenith
      or Nadir shots. I usually don't have time to manually add control
      points (which I often need to do with the Zenith and Nadir) so I tried
      making them without and they work OK. When I do this, however, I get
      small black boxes at the top and bottom that need a bit of covering but
      that's easily done.

      The problem I'm having is that the areas around the black boxes are a
      hazy black. I see what's causing it, but I have NO idea how to fix
      it. I believe that when the 4 images are finally blended, the black
      overhang gets blended with the ceiling (usually a light color) and
      causes a black haze.

      Does anyone have any ideas how to fix this?

      -Jeremy
    • John Houghton
      ... Prevention is better than cure. Just tilt the camera up a little so that the zenith is fully covered. You can also often improve the blending in that
      Message 2 of 10 , Oct 26, 2007
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        --- In PanoToolsNG@yahoogroups.com, "Jeremy" <discaholic@...> wrote:
        > I believe that when the 4 images are finally blended, the black
        > overhang gets blended with the ceiling (usually a light color) and
        > causes a black haze.

        Prevention is better than cure. Just tilt the camera up a little so
        that the zenith is fully covered. You can also often improve the
        blending in that area by rotating the whole panorama image to bring the
        zenith down to the centre of the output area using the numerical
        transform option. Remap afterwards to the normal position.

        John
      • Erik Krause
        ... As long as you don t provide additional details about your workflow - no. I don t know whether I can speak for all, but I believe none of us does have
        Message 3 of 10 , Oct 26, 2007
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          On Friday, October 26, 2007 at 6:40, Jeremy wrote:

          > The problem I'm having is that the areas around the black boxes are a
          > hazy black. I see what's causing it, but I have NO idea how to fix
          > it. I believe that when the 4 images are finally blended, the black
          > overhang gets blended with the ceiling (usually a light color) and
          > causes a black haze.
          >
          > Does anyone have any ideas how to fix this?

          As long as you don't provide additional details about your workflow -
          no. I don't know whether I can speak for all, but I believe none of
          us does have second sight...

          It could be that any of the blenders (whatever it is) is causing it,
          but on the other hand your stitching application (whatever it is)
          should pass masked images to the blender.

          If it is a circular fisheye may be you didn't crop to inside the
          image circle (in which case the dark border is part of the image) but
          all these are wild guesses...

          best regards
          --
          http://www.erik-krause.de
        • Jeremy
          Hey Erik, When I crop the images, I avoid the black haze, but end up with an image that is NOT equirectangular. So I must put the image into Photoshop to add
          Message 4 of 10 , Oct 29, 2007
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            Hey Erik,

            When I crop the images, I avoid the black haze, but end up with an
            image that is NOT equirectangular. So I must put the image into
            Photoshop to add some white space at the top and bottom. This gives
            me a MUCH larger square at the top and bottom of the image (in the
            pano).

            Here's is an example of what I'm talking about with the black haze
            www.vli.com/hazetestshot

            BTW, I'm using a Cannon Xti, Sigma 8mm 3.5, and PTGui 7.2

            -Jeremy


            --- In PanoToolsNG@yahoogroups.com, "Erik Krause" <erik.krause@...>
            wrote:
            >
            > On Friday, October 26, 2007 at 6:40, Jeremy wrote:
            >
            > > The problem I'm having is that the areas around the black boxes
            are a
            > > hazy black. I see what's causing it, but I have NO idea how to
            fix
            > > it. I believe that when the 4 images are finally blended, the
            black
            > > overhang gets blended with the ceiling (usually a light color)
            and
            > > causes a black haze.
            > >
            > > Does anyone have any ideas how to fix this?
            >
            > As long as you don't provide additional details about your
            workflow -
            > no. I don't know whether I can speak for all, but I believe none of
            > us does have second sight...
            >
            > It could be that any of the blenders (whatever it is) is causing
            it,
            > but on the other hand your stitching application (whatever it is)
            > should pass masked images to the blender.
            >
            > If it is a circular fisheye may be you didn't crop to inside the
            > image circle (in which case the dark border is part of the image)
            but
            > all these are wild guesses...
            >
            > best regards
            > --
            > http://www.erik-krause.de
            >
          • John Houghton
            ... Jeremy, your link doesn t work. If you set the output panorama format to be a 360x180 equirectangular image before generating the panorama then that is
            Message 5 of 10 , Oct 30, 2007
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              --- In PanoToolsNG@yahoogroups.com, "Jeremy" <discaholic@...> wrote:
              >
              > Here's is an example of what I'm talking about with the black haze
              > www.vli.com/hazetestshot

              Jeremy, your link doesn't work.

              If you set the output panorama format to be a 360x180 equirectangular
              image before generating the panorama then that is what you will get.
              Do this from the Panorama Editor window: either via the Projection
              menu or simply press ctrl+shift+H. Blank space at the top is to be
              expected if you keep the camera level but can be eliminated by tilting
              the camera up by about 5 degrees. Another cause is inadequate lens
              parameter values. See this thread for further discussion:

              http://tech.groups.yahoo.com/group/PanoToolsNG/message/13922

              John
            • Erik Krause
              ... You should crop the input images in PTGui such that the crop circle is inside the actual image circle border... best regards -- http://www.erik-krause.de
              Message 6 of 10 , Nov 2, 2007
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                On Tuesday, October 30, 2007 at 5:33, Jeremy wrote:

                > When I crop the images, I avoid the black haze, but end up with an
                > image that is NOT equirectangular

                You should crop the input images in PTGui such that the crop circle
                is inside the actual image circle border...

                best regards
                --
                http://www.erik-krause.de
              • Jeremy
                Argh. That s what I get for working til 3am! :) Here s the black hazy shot. www.vli.com/hazetestshot.gif -Jeremy ... equirectangular ... get. ... tilting
                Message 7 of 10 , Nov 5, 2007
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                  Argh. That's what I get for working til 3am! :) Here's the
                  black hazy shot.

                  www.vli.com/hazetestshot.gif

                  -Jeremy

                  --- In PanoToolsNG@yahoogroups.com, "John Houghton" <j.houghton@...>
                  wrote:
                  >
                  > --- In PanoToolsNG@yahoogroups.com, "Jeremy" <discaholic@> wrote:
                  > >
                  > > Here's is an example of what I'm talking about with the black haze
                  > > www.vli.com/hazetestshot
                  >
                  > Jeremy, your link doesn't work.
                  >
                  > If you set the output panorama format to be a 360x180
                  equirectangular
                  > image before generating the panorama then that is what you will
                  get.
                  > Do this from the Panorama Editor window: either via the Projection
                  > menu or simply press ctrl+shift+H. Blank space at the top is to be
                  > expected if you keep the camera level but can be eliminated by
                  tilting
                  > the camera up by about 5 degrees. Another cause is inadequate lens
                  > parameter values. See this thread for further discussion:
                  >
                  > http://tech.groups.yahoo.com/group/PanoToolsNG/message/13922
                  >
                  > John
                  >
                • John Houghton
                  ... Jeremy, It doesn t look like you have cropped the images in any way. As Erik pointed out, this is essential. You should either apply a circular crop in
                  Message 8 of 10 , Nov 6, 2007
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                    --- In PanoToolsNG@yahoogroups.com, "Jeremy" <discaholic@...> wrote:
                    >
                    > Argh. That's what I get for working til 3am!

                    Jeremy, It doesn't look like you have cropped the images in any way.
                    As Erik pointed out, this is essential. You should either apply a
                    circular crop in PTGui or Hugin to mask away the blak parts, (the
                    obvious way), or use an alpha channel mask.

                    John
                  • John Houghton
                    Just a thought: have you made the classic mistake of not removing the push-fit collar that holds the lens cap on a Sigma 8mm lens? I think that reduces the
                    Message 9 of 10 , Nov 6, 2007
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                      Just a thought: have you made the classic mistake of not removing the
                      push-fit collar that holds the lens cap on a Sigma 8mm lens? I think
                      that reduces the fov to 140 degrees, as seems to be the case in your
                      image.

                      John
                    • Sacha Griffin
                      It almost appears your neighbors with Jim waters.. It s similar to his CA test pano I studied intensively. I honestly am not really sure. I leave tripod junk
                      Message 10 of 10 , Nov 7, 2007
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                        It almost appears your neighbors with Jim waters.. It's similar to his CA
                        test pano I studied intensively.

                        I honestly am not really sure. I leave tripod junk in my shots every time
                        and ptgui with ptgui/blender is able to recognize it and not blend it.

                        Unless it occurs in every frame in the same spot which is what could be the
                        problem. Either crop it out or open each photo in photoshop,

                        Create an alpha channel, select the alpha channel and paint the offending
                        junk away.



                        Sacha Griffin
                        Southern Digital Solutions LLC - Atlanta, Georgia
                        www.southern-digital.com
                        www.seeit360.net
                        www.ezphotosafe.com
                        404-551-4275
                        404-731-7798

                        _____

                        From: PanoToolsNG@yahoogroups.com [mailto:PanoToolsNG@yahoogroups.com] On
                        Behalf Of Jeremy
                        Sent: Tuesday, November 06, 2007 2:16 AM
                        To: PanoToolsNG@yahoogroups.com
                        Subject: [PanoToolsNG] Re: Weird black haze when shooting without Zenith and
                        Nadir shots



                        Argh. That's what I get for working til 3am! :) Here's the
                        black hazy shot.

                        www.vli.com/hazetestshot.gif

                        -Jeremy

                        --- In PanoToolsNG@ <mailto:PanoToolsNG%40yahoogroups.com> yahoogroups.com,
                        "John Houghton" <j.houghton@...>
                        wrote:
                        >
                        > --- In PanoToolsNG@ <mailto:PanoToolsNG%40yahoogroups.com>
                        yahoogroups.com, "Jeremy" <discaholic@> wrote:
                        > >
                        > > Here's is an example of what I'm talking about with the black haze
                        > > www.vli.com/hazetestshot
                        >
                        > Jeremy, your link doesn't work.
                        >
                        > If you set the output panorama format to be a 360x180
                        equirectangular
                        > image before generating the panorama then that is what you will
                        get.
                        > Do this from the Panorama Editor window: either via the Projection
                        > menu or simply press ctrl+shift+H. Blank space at the top is to be
                        > expected if you keep the camera level but can be eliminated by
                        tilting
                        > the camera up by about 5 degrees. Another cause is inadequate lens
                        > parameter values. See this thread for further discussion:
                        >
                        > http://tech.
                        <http://tech.groups.yahoo.com/group/PanoToolsNG/message/13922>
                        groups.yahoo.com/group/PanoToolsNG/message/13922
                        >
                        > John
                        >





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