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Combining binned and unbinned

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  • Ivor Barker
    I have seen all of these wonderful LRGB images around and noticed that a lot of then have binned RGB and unbinned L. How does one combine binned and unbinned
    Message 1 of 9 , Nov 17, 2000
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      I have seen all of these wonderful LRGB images around and noticed that a lot of then have binned RGB and unbinned L. How does one combine binned and unbinned since they are different sizes?

      Oh I think I just realized, just resize (shrink) the unbinned ?

      Cheers !!

      --
      Ivor Barker
      10" LX 200
      ST-237
      37 08 24 N
      121 36 25 W
      http://www.employees.org/~ibarker/Astronomy
      Please take a look at my Messier Project (updated daily - almost)
      http://www.employees.org/~ibarker/Astronomy/Messier.html
    • Ron Wodaski
      Close. You increase the size of the binned (color) components to match the unbinned Luminance layer. The eye is less sensitive to color detail that to
      Message 2 of 9 , Nov 17, 2000
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        Close. You increase the size of the binned (color) components to match the
        unbinned Luminance layer. The eye is less sensitive to color detail that to
        luminance detail, so this works reasonably well.

        But if you have the time and inclination to do the colors at 1x1, you can
        see a difference. But you need really long integrations to make this work.
        Last night, I did M33. The luminance layer was 5 minutes; the RGB were
        10:10:16 minutes! Big difference. I took five or six luminance, and three
        sets of RGB. It took me, what, about 40 minutes for each RGB set, versus
        about a half hour for all of the luminance images. But I think that when I
        am able to process these images, they should be really nice.

        Ron Wodaski
        The New Astronomy Book Site - http://www.newastro.com



        -----Original Message-----
        From: Ivor Barker [mailto:ibarker@...]
        Sent: Friday, November 17, 2000 5:57 PM
        To: ccd-newastro@egroups.com
        Subject: [ccd-newastro] Combining binned and unbinned


        I have seen all of these wonderful LRGB images around and noticed that a lot
        of then have binned RGB and unbinned L. How does one combine binned and
        unbinned since they are different sizes?

        Oh I think I just realized, just resize (shrink) the unbinned ?

        Cheers !!

        --
        Ivor Barker
        10" LX 200
        ST-237
        37 08 24 N
        121 36 25 W
        http://www.employees.org/~ibarker/Astronomy
        Please take a look at my Messier Project (updated daily - almost)
        http://www.employees.org/~ibarker/Astronomy/Messier.html



        To unsubscribe from this group, send an email to:
        ccd-newastro-unsubscribe@egroups.com
      • KSBTK@HOME
        Good evening Ron: Here s another one of my dense questions. Can you please explain the concept of luminance again. With my ST-237, how do i do that? Clear
        Message 3 of 9 , Nov 17, 2000
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          Good evening Ron:

          Here's another one of my dense questions. Can you please explain the
          concept of luminance again. With my ST-237, how do i do that?

          Clear skies,
          Kevin
          ksbtk@...

          From: "Ron Wodaski" <ronw@...>

          > Close. You increase the size of the binned (color) components to match the
          > unbinned Luminance layer. The eye is less sensitive to color detail that
          to
          > luminance detail, so this works reasonably well.
          >
          > But if you have the time and inclination to do the colors at 1x1, you can
          > see a difference. But you need really long integrations to make this work.
          > Last night, I did M33. The luminance layer was 5 minutes; the RGB were
          > 10:10:16 minutes! Big difference. I took five or six luminance, and three
          > sets of RGB. It took me, what, about 40 minutes for each RGB set, versus
          > about a half hour for all of the luminance images. But I think that when I
          > am able to process these images, they should be really nice.
        • Ron Wodaski
          Luminance is simply the non-color information in your images (that is, brightness levels; that which you see if you convert to grayscale). You can take RGB
          Message 4 of 9 , Nov 17, 2000
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            Luminance is simply the non-color information in your images (that is,
            brightness levels; that which you see if you convert to grayscale). You can
            take RGB images and combine them, and the luminance information from the
            color channels is used to create the luminance channel.

            Or, you can take a separate luminance image or set of images, and make up an
            LRGB image. The advantage to taking a separate luminance channel is that you
            get better signal-to-noise in the brightness data; the down side is that you
            tend to wash out your colors somewhat.

            Generally speaking, the eye is most sensitive to brightness levels; color
            sensitivity isn't as precise. Many color encoding schemes (for example,
            video) devote more bandwidth to luminance than to color for this reason.

            Ron Wodaski
            The New Astronomy Book Site - http://www.newastro.com



            -----Original Message-----
            From: KSBTK@HOME [mailto:ksbtk@...]
            Sent: Friday, November 17, 2000 6:53 PM
            To: ccd-newastro@egroups.com
            Subject: Re: [ccd-newastro] Combining binned and unbinned


            Good evening Ron:

            Here's another one of my dense questions. Can you please explain the
            concept of luminance again. With my ST-237, how do i do that?

            Clear skies,
            Kevin
            ksbtk@...

            From: "Ron Wodaski" <ronw@...>

            > Close. You increase the size of the binned (color) components to match the
            > unbinned Luminance layer. The eye is less sensitive to color detail that
            to
            > luminance detail, so this works reasonably well.
            >
            > But if you have the time and inclination to do the colors at 1x1, you can
            > see a difference. But you need really long integrations to make this work.
            > Last night, I did M33. The luminance layer was 5 minutes; the RGB were
            > 10:10:16 minutes! Big difference. I took five or six luminance, and three
            > sets of RGB. It took me, what, about 40 minutes for each RGB set, versus
            > about a half hour for all of the luminance images. But I think that when I
            > am able to process these images, they should be really nice.





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          • KSBTK@HOME
            Good Morning Ron: If one were going to creat a separte luminance image or set of images, how would you do that with the ST-237. Is itsimply a matter of using
            Message 5 of 9 , Nov 17, 2000
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              Good Morning Ron:

              If one were going to creat a separte luminance image or set of images, how
              would you do that with the ST-237. Is itsimply a matter of using the clear
              filter?

              Clea skies,
              Kevin
              ksbtk@...

              From: "Ron Wodaski" <ronw@...>

              > Or, you can take a separate luminance image or set of images, and make up
              an
              > LRGB image. The advantage to taking a separate luminance channel is that
              you
              > get better signal-to-noise in the brightness data; the down side is that
              you
              > tend to wash out your colors somewhat.
            • Ron Wodaski
              Right. That s all there is to it. Ron Wodaski The New Astronomy Book Site - http://www.newastro.com ... From: KSBTK@HOME [mailto:ksbtk@home.com] Sent: Friday,
              Message 6 of 9 , Nov 17, 2000
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                Right. That's all there is to it.

                Ron Wodaski
                The New Astronomy Book Site - http://www.newastro.com



                -----Original Message-----
                From: KSBTK@HOME [mailto:ksbtk@...]
                Sent: Friday, November 17, 2000 11:22 PM
                To: ccd-newastro@egroups.com
                Subject: Re: [ccd-newastro] Combining binned and unbinned


                Good Morning Ron:

                If one were going to creat a separte luminance image or set of images, how
                would you do that with the ST-237. Is itsimply a matter of using the clear
                filter?

                Clea skies,
                Kevin
                ksbtk@...

                From: "Ron Wodaski" <ronw@...>

                > Or, you can take a separate luminance image or set of images, and make up
                an
                > LRGB image. The advantage to taking a separate luminance channel is that
                you
                > get better signal-to-noise in the brightness data; the down side is that
                you
                > tend to wash out your colors somewhat.





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                ccd-newastro-unsubscribe@egroups.com
              • KSBTK@HOME
                Good Morning Ron: I think I am beginning to understand . I have several questions. Are there objects for which LRGB is best suited or is it applicable to
                Message 7 of 9 , Nov 18, 2000
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                  Good Morning Ron:

                  I think I am beginning to understand <g>.

                  I have several questions. Are there objects for which LRGB is best suited
                  or is it applicable to all DSOs? How do you determine the ratio in terms of
                  exposure? Using my ST-237 in Fastar mode as an example, the best I can
                  manage from my C8-D with unguided exposures (and no star trailing) is a 90
                  second exposure. I f I were imaging the horsehead nebula (have you noticed
                  how I am obsessed with that horsehead? <g>) and were taking RGB exposures at
                  a ratio of 1:1:1.5 (60 seconds: 60 seconds: 90 seconds), I would generate 25
                  each RGB images. How many luminance images would I generate and what would
                  be their duration? Would I take them at high resolution (unbinned), medium
                  resolution (2x2) or low resolution (3x3)?

                  So many questions <g>

                  Clear skies,
                  Kevin ksbtk@...


                  From: "Ron Wodaski" <ronw@...>

                  > Right. That's all there is to it.
                  >
                  > Ron Wodaski

                  > From: KSBTK@HOME [mailto:ksbtk@...]
                  >
                  > If one were going to creat a separte luminance image or set of images, how
                  > would you do that with the ST-237. Is itsimply a matter of using the
                  clear
                  > filter?
                • Paul Sterngold
                  The same LRGB image would take me a minimum of 5+5+10+10+10+10+16+16 minutes = 82 minutes total exposure time. Why? Because my blasted MX916 camera has
                  Message 8 of 9 , Nov 18, 2000
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                    The same LRGB image would take me a minimum of 5+5+10+10+10+10+16+16 minutes = 82
                    minutes total exposure time. Why? Because my blasted MX916 camera has "open-loop
                    cooling." In other words, there is no "set-point," the camera simply goes on full
                    cooler all the time. In addition, there is no temp sensor in the head. This means that
                    I *always* have to take a fresh dark frame immediately before or after taking an image
                    frame.

                    I try to take two dark frames, one immediately before and one immediately after each
                    exposure, so I can average them. Thus, my actual exposure time for this image would be
                    103 minutes total (add 5 mins before the first image and 16 mins after the last). It
                    would probably take me close to two hours to take the frames for it. I can only dream
                    about the time savings I could have, if I had a camera with "closed-loop cooling" and a
                    temp sensor. <sigh>

                    Paul Sterngold

                    --- Ron Wodaski <ronw@...> wrote:
                    > Close. You increase the size of the binned (color) components to match the
                    > unbinned Luminance layer. The eye is less sensitive to color detail that to
                    > luminance detail, so this works reasonably well.
                    >
                    > But if you have the time and inclination to do the colors at 1x1, you can
                    > see a difference. But you need really long integrations to make this work.
                    > Last night, I did M33. The luminance layer was 5 minutes; the RGB were
                    > 10:10:16 minutes! Big difference. I took five or six luminance, and three
                    > sets of RGB. It took me, what, about 40 minutes for each RGB set, versus
                    > about a half hour for all of the luminance images. But I think that when I
                    > am able to process these images, they should be really nice.
                    >
                    > Ron Wodaski
                    > The New Astronomy Book Site - http://www.newastro.com
                    >
                    >
                    >
                    > -----Original Message-----
                    > From: Ivor Barker [mailto:ibarker@...]
                    > Sent: Friday, November 17, 2000 5:57 PM
                    > To: ccd-newastro@egroups.com
                    > Subject: [ccd-newastro] Combining binned and unbinned
                    >
                    >
                    > I have seen all of these wonderful LRGB images around and noticed that a lot
                    > of then have binned RGB and unbinned L. How does one combine binned and
                    > unbinned since they are different sizes?
                    >
                    > Oh I think I just realized, just resize (shrink) the unbinned ?
                    >
                    > Cheers !!
                    >
                    > --
                    > Ivor Barker
                    > 10" LX 200
                    > ST-237
                    > 37 08 24 N
                    > 121 36 25 W
                    > http://www.employees.org/~ibarker/Astronomy
                    > Please take a look at my Messier Project (updated daily - almost)
                    > http://www.employees.org/~ibarker/Astronomy/Messier.html
                    >
                    >
                    >
                    > To unsubscribe from this group, send an email to:
                    > ccd-newastro-unsubscribe@egroups.com
                    >
                    >
                    >
                    >
                    >


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                  • Kevin Dixon
                    Good Morning Ron: If you get a moment, could you please respond to my questions below. I am hoping to experiment with this and flat fielding this week. Thanks.
                    Message 9 of 9 , Nov 26, 2000
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                      Good Morning Ron:

                      If you get a moment, could you please respond to my questions below.
                      I am hoping to experiment with this and flat fielding this week.
                      Thanks.

                      Clear skies,
                      Kevin
                      ksbtk@...

                      In ccd-newastro@egroups.com, "KSBTK@H..." <ksbtk@h...> wrote:
                      I have several questions. Are there objects for which LRGB is best
                      suited or is it applicable to all DSOs? How do you determine the
                      ratio in terms of exposure? Using my ST-237 in Fastar mode as an
                      example, the best I can manage from my C8-D with unguided exposures
                      (and no star trailing) is a 90 second exposure. If I were imaging
                      the horsehead nebula (have you noticed how I am obsessed with that
                      horsehead? <g>) and were taking RGB exposures at a ratio of 1:1:1.5
                      (60 seconds: 60 seconds: 90 seconds), I would generate 25 each RGB
                      images. How many luminance images would I generate and what would be
                      their duration? Would I take them at high resolution (unbinned),
                      medium resolution (2x2) or low resolution (3x3)?

                      > From: "Ron Wodaski" <ronw@n...>
                      >
                      > > Right. That's all there is to it.
                      > >
                      > > Ron Wodaski
                      >
                      > > From: KSBTK@HOME [mailto:ksbtk@h...]
                      > >
                      > > If one were going to creat a separte luminance image or set of
                      images, how
                      > > would you do that with the ST-237. Is itsimply a matter of using
                      the
                      > clear
                      > > filter?
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