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RE: [ccd-newastro] New image for critical input

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  • Wodaski - Yahoo
    The red in this image is very strong relative to the other channels. If you look at in the Histogram palette, with All channels view and Show channels in
    Message 1 of 3 , Apr 30, 2008
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      The red in this image is very strong relative to the other channels. If you
      look at in the Histogram palette, with "All channels view" and "Show
      channels in color," you can see this very clearly. I used Color balance to
      apply -45 to the red channel to get somewhere close to balance. (This
      reveals clipping in the red channel, so I can't really achieve correct
      balance, but with an offset that large, there are bound to be other issues
      surfacing...)

      After that adjustment, green is a little low. However, I think the black
      point in green might have been set a little low as well, so you wind up with
      a somewhat green background from bias.

      Sorry to rub some salt in the wound, but there are also large dark haols
      around the stars; that often happens from sharpening too much.

      On the plus side, you do have some nice data there and once you learn to
      tame it, you'll have a very nice image.

      Ron Wodaski

      -----Original Message-----
      From: ccd-newastro@yahoogroups.com [mailto:ccd-newastro@yahoogroups.com] On
      Behalf Of olivierfp
      Sent: Wednesday, April 30, 2008 8:11 PM
      To: ccd-newastro@yahoogroups.com
      Subject: [ccd-newastro] New image for critical input

      Hello All,
      I have uploaded a file called M101 LRGB.jpg in the files section
      hoping to get input on what looks ok and what does not look ok in my
      treatment
      This follows a very recent input from Ron on color balancing.
      Background: Borg 101ED @ F/6.4 on a GM8 Gemini. Image is an ST8 with
      CFW8 and Astrodon LRGB filters. 210 minutes for luminance and about 60
      minutes for R, G,B.
      Calibration, data rejection align and stack done with CCDStack.
      The rest is all done in CS2 where each primary is stretched, somewhat
      background compensated and then combined.
      There is a gradient that I could not remove completely (I am only
      using ccdstack and CS2), and guiding on the luminance frames was not
      as good as on the color frames.
      Thanks in advance for any input you may have
      Olivier


      ------------------------------------
    • olivierfp
      Ron, Thank you for the input, this is exactly what I was looking for. It will be back to the drawing board later this week. As you siad, there is data to
      Message 2 of 3 , May 1 10:19 AM
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        Ron,
        Thank you for the input, this is exactly what I was looking for.
        It will be back to the "drawing board" later this week. As you siad,
        there is data to work with and I am just starting.
        Regards,
        Olivier
        --- In ccd-newastro@yahoogroups.com, "Wodaski - Yahoo" <yahoo@...> wrote:
        >
        > The red in this image is very strong relative to the other channels.
        If you
        > look at in the Histogram palette, with "All channels view" and "Show
        > channels in color," you can see this very clearly. I used Color
        balance to
        > apply -45 to the red channel to get somewhere close to balance. (This
        > reveals clipping in the red channel, so I can't really achieve correct
        > balance, but with an offset that large, there are bound to be other
        issues
        > surfacing...)
        >
        > After that adjustment, green is a little low. However, I think the black
        > point in green might have been set a little low as well, so you wind
        up with
        > a somewhat green background from bias.
        >
        > Sorry to rub some salt in the wound, but there are also large dark haols
        > around the stars; that often happens from sharpening too much.
        >
        > On the plus side, you do have some nice data there and once you learn to
        > tame it, you'll have a very nice image.
        >
        > Ron Wodaski
        >
        > -----Original Message-----
        > From: ccd-newastro@yahoogroups.com
        [mailto:ccd-newastro@yahoogroups.com] On
        > Behalf Of olivierfp
        > Sent: Wednesday, April 30, 2008 8:11 PM
        > To: ccd-newastro@yahoogroups.com
        > Subject: [ccd-newastro] New image for critical input
        >
        > Hello All,
        > I have uploaded a file called M101 LRGB.jpg in the files section
        > hoping to get input on what looks ok and what does not look ok in my
        > treatment
        > This follows a very recent input from Ron on color balancing.
        > Background: Borg 101ED @ F/6.4 on a GM8 Gemini. Image is an ST8 with
        > CFW8 and Astrodon LRGB filters. 210 minutes for luminance and about 60
        > minutes for R, G,B.
        > Calibration, data rejection align and stack done with CCDStack.
        > The rest is all done in CS2 where each primary is stretched, somewhat
        > background compensated and then combined.
        > There is a gradient that I could not remove completely (I am only
        > using ccdstack and CS2), and guiding on the luminance frames was not
        > as good as on the color frames.
        > Thanks in advance for any input you may have
        > Olivier
        >
        >
        > ------------------------------------
        >
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