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RE: [ccd-newastro] Re: Binning question

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  • Wodaski - Yahoo
    That s not quite correct. Let me explain. When you bin 2x2, you are not reducing the read noise; you are increasing the signal relative to the read noise by
    Message 1 of 22 , Oct 4, 2007
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      That's not quite correct. Let me explain.

      When you bin 2x2, you are not reducing the read noise; you are increasing
      the signal relative to the read noise by combining signal from multiple
      pixels. So you get more signal, but the same read noise (one does of read
      noise per read).

      Also, the benefit from this depends on the length of the exposure. If your
      individual exposure times are reasonably optimal (that is, the read noise is
      1/15th or less of the total shot noise), then there is little to no benefit
      from binning. SO the brighter your skies, the less improvement you will see
      from this technique. The darker your skies, and the shorter your exposure
      times, the more likely you are to see a benefit from binning.

      Ron Wodaski

      -----Original Message-----
      From: ccd-newastro@yahoogroups.com [mailto:ccd-newastro@yahoogroups.com] On
      Behalf Of Paul K
      Sent: Thursday, October 04, 2007 6:00 AM
      To: ccd-newastro@yahoogroups.com
      Subject: [ccd-newastro] Re: Binning question

      Hi Eddy,

      Binning has one advantage over not binning: it reduces the read-out
      noise of the camera. When taking filtered exposures of faint
      objects, read-out noise can be the dominant noise in the image, so
      it may be advantageous to bin RGB frames, especially in LRGB imaging.

      But, if your RGB exposure is long enough to overcome read-out
      noise, or the object is bright enough to drown out this noise,
      there's no good reason to bin (maybe just one: the images are
      smaller and download faster <g>)

      If you bin 2x2, the image scale will be twice that of 1x1, i.e., one-
      half the resolution. To register and combine binned images with
      unbinned you can manually resize the image to 200%, or use software
      that can do this for you automatically (CCDStack, Registar, etc.)

      Regards,

      -Paul


      --- In ccd-newastro@yahoogroups.com, "Eddy" <EddyMuriel@...> wrote:
      >
      > Hi all,
      >
      > Could somebody, in a few words, explain me why one would use
      binning?
      >
      > I see that some imagers are binning 2x2 the RGB channels but using
      1x1
      > for the luminance. Others are using 1x1 for all the channels. To
      me,
      > both ways look the same.
      >
      > I understand that binning 2x2 will reduce exposure times. But that
      is
      > the only "advantage" I am seeing.
      > When binning 2x2, the image scale will be different - if I
      understood
      > this correctly - than with 1x1.
      > How do you convert or stack these? Do you have to change the image
      > size before stacking?
      >
      > Thanks for any info,
      > Eddy
      >




      Yahoo! Groups Links
    • Wodaski - Yahoo
      ... It s all about the noise. Blurring reduces color noise. Blurring and binning are just two techniques you can use to allow shorter exposure times. This will
      Message 2 of 22 , Oct 4, 2007
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        >> Why blur these frames?

        It's all about the noise. Blurring reduces color noise.

        Blurring and binning are just two techniques you can use to allow shorter
        exposure times. This will keep the color in the bright areas, but hide the
        dominance of noise in the dimmer areas.

        If you are willing to take sufficiently long exposures, you don't need to
        use such tricks. So it's a trade-off: you can take shorter individual
        exposures and less total exposure time, and then use some tricks to hide the
        resulting noise. Or you can take lots of time to expose, and have better
        color from the get-go.

        This might seem trivial, but it takes hour and hours of exposure time to get
        beyond the need for tricks! Not that many people are willing to take that
        route because of the time required to do it.

        Ron W

        -----Original Message-----
        From: ccd-newastro@yahoogroups.com [mailto:ccd-newastro@yahoogroups.com] On
        Behalf Of Eddy
        Sent: Thursday, October 04, 2007 9:44 AM
        To: ccd-newastro@yahoogroups.com
        Subject: [ccd-newastro] Re: Binning question

        --- In ccd-newastro@yahoogroups.com, Mike Dodd <mike_dodd@...> wrote:
        >
        > you are correct; binning 2x2 creates a "super pixel" with four times
        the
        > area of a single pixel, so it's four times more sensitive. Color
        filters
        > typically reduce the amount of light reaching the chip, so this
        > increased sensitivity avoids having to take extremely long RGB
        > exposures.the other benefit comets from using the color channels in
        > conjunction with am unbinned luminance channel. the luminance channel
        > provides the sharpness and detail, while the color channels don't have
        > to be so sharp. In fact,many people blur the color channels before
        > layering in Photoshop to form the LRGB image.
        >
        > You are correct about the image scale, but all that really affects is
        > the resolution, which isn't important if you're going to blur the RGB
        > channels anyway. the color frames are resized (doubled in each
        > dimension) before combining to match the luminance frame size.
        >
        Thank you Mike. But why blur these frames? I am afraid I don't quite
        understand this. Wouldn't the image look nicer when they are not
        blurred or have a better resolution.
        I never did this, so it is maybe easier to understand when combining a
        LRGB.

        Eddy



        Yahoo! Groups Links
      • Mike Dodd
        ... with an LRGB image, the color channels are combined with the luminance channel using a color blending mode. In this case, the luminance channel provides
        Message 3 of 22 , Oct 4, 2007
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          Eddy wrote:
          >>
          > Thank you Mike. But why blur these frames? I am afraid I don't quite
          > understand this. Wouldn't the image look nicer when they are not
          > blurred or have a better resolution.
          > I never did this, so it is maybe easier to understand when combining a
          > LRGB.


          with an LRGB image, the color channels are combined with the luminance
          channel using a "color" blending mode. In this case, the luminance
          channel provides the details, and the color channels can be blurred. Try
          it for yourself to see the color combine in action. It always brings a
          smile to my face to see the fine color details appear after I select the
          color blending mode, especially knowing that the color channels are
          intentionally blurred.

          --- Mike
          --

          Mike Dodd
          Montpelier, VA USA
          http://astronomy.mdodd.com
        • Eddy
          Ok, Thank you, Ron. I am understanding it now and I guess I have to try the technique so see for myself. I do have time (I am retired), so I could skip the
          Message 4 of 22 , Oct 4, 2007
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            Ok, Thank you, Ron. I am understanding it now and I guess I have to
            try the technique so see for myself.

            I do have time (I am retired), so I could skip the binning technique,
            but the main problem is that the weather is not always cooperative...
            I guess this is also a reason for binning. Unless somebody could wait
            a couple of months before having a nice picture.

            Thank you,
            Eddy
          • Paul K
            Sorry to disagree with you, Ron :) Binning does indeed reduce read noise: each binned super pixel is read only once, so the amount of read noise is halved for
            Message 5 of 22 , Oct 4, 2007
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              Sorry to disagree with you, Ron :)

              Binning does indeed reduce read noise: each binned super pixel is
              read only once, so the amount of read noise is halved for the same
              area of the sky when binned 2x2. When binned 1x1, four pixels are
              read, resulting in 2x the amount of read noise (sqrt(4)).

              The amount of signal does not increase when binning: the same number
              of photons are received by the 2x2 super pixel as the total received
              by the four underlying pixels.

              Regards,

              -Paul

              --- In ccd-newastro@yahoogroups.com, "Wodaski - Yahoo" <yahoo@...>
              wrote:
              >
              > That's not quite correct. Let me explain.
              >
              > When you bin 2x2, you are not reducing the read noise; you are
              increasing
              > the signal relative to the read noise by combining signal from
              multiple
              > pixels. So you get more signal, but the same read noise (one does
              of read
              > noise per read).
              >
              > Also, the benefit from this depends on the length of the exposure.
              If your
              > individual exposure times are reasonably optimal (that is, the
              read noise is
              > 1/15th or less of the total shot noise), then there is little to
              no benefit
              > from binning. SO the brighter your skies, the less improvement you
              will see
              > from this technique. The darker your skies, and the shorter your
              exposure
              > times, the more likely you are to see a benefit from binning.
              >
              > Ron Wodaski
              >
              > -----Original Message-----
              > From: ccd-newastro@yahoogroups.com [mailto:ccd-
              newastro@yahoogroups.com] On
              > Behalf Of Paul K
              > Sent: Thursday, October 04, 2007 6:00 AM
              > To: ccd-newastro@yahoogroups.com
              > Subject: [ccd-newastro] Re: Binning question
              >
              > Hi Eddy,
              >
              > Binning has one advantage over not binning: it reduces the read-
              out
              > noise of the camera. When taking filtered exposures of faint
              > objects, read-out noise can be the dominant noise in the image, so
              > it may be advantageous to bin RGB frames, especially in LRGB
              imaging.
              >
              > But, if your RGB exposure is long enough to overcome read-out
              > noise, or the object is bright enough to drown out this noise,
              > there's no good reason to bin (maybe just one: the images are
              > smaller and download faster <g>)
              >
              > If you bin 2x2, the image scale will be twice that of 1x1, i.e.,
              one-
              > half the resolution. To register and combine binned images with
              > unbinned you can manually resize the image to 200%, or use
              software
              > that can do this for you automatically (CCDStack, Registar, etc.)
              >
              > Regards,
              >
              > -Paul
              >
              >
              > --- In ccd-newastro@yahoogroups.com, "Eddy" <EddyMuriel@> wrote:
              > >
              > > Hi all,
              > >
              > > Could somebody, in a few words, explain me why one would use
              > binning?
              > >
              > > I see that some imagers are binning 2x2 the RGB channels but
              using
              > 1x1
              > > for the luminance. Others are using 1x1 for all the channels. To
              > me,
              > > both ways look the same.
              > >
              > > I understand that binning 2x2 will reduce exposure times. But
              that
              > is
              > > the only "advantage" I am seeing.
              > > When binning 2x2, the image scale will be different - if I
              > understood
              > > this correctly - than with 1x1.
              > > How do you convert or stack these? Do you have to change the
              image
              > > size before stacking?
              > >
              > > Thanks for any info,
              > > Eddy
              > >
              >
              >
              >
              >
              > Yahoo! Groups Links
              >
            • Wodaski - Yahoo
              We are not really disagreeing. I didn t say there was more signal. I said there was more signal _relative to the read noise_. My point was that the read noise
              Message 6 of 22 , Oct 4, 2007
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                We are not really disagreeing. I didn't say there was more signal. I said
                there was more signal _relative to the read noise_.

                My point was that the read noise is constant per read: you read once, you
                get one dose of read noise. In that sense, the read noise does not change.
                This is what I wanted to emphasize: that read noise is a constant, one dose
                per read. Binning simply applies that noise to more than one pixel,
                increasing S/N.

                In the end, what is important with binning is that the _ratio_ of signal to
                read noise is different.

                Note that it is important to remember that this is only important if read
                noise is a significant component of total noise. If you have long enough
                sub-exposures, then by definition read noise is a small part of the total
                noise and binning will make very little difference in the signal to noise
                ratio. (Shot noise changes with the signal; shot noise is the square root of
                the signal.)

                Ron Wodaski

                -----Original Message-----
                From: ccd-newastro@yahoogroups.com [mailto:ccd-newastro@yahoogroups.com] On
                Behalf Of Paul K
                Sent: Thursday, October 04, 2007 10:08 AM
                To: ccd-newastro@yahoogroups.com
                Subject: [ccd-newastro] Re: Binning question

                Sorry to disagree with you, Ron :)

                Binning does indeed reduce read noise: each binned super pixel is
                read only once, so the amount of read noise is halved for the same
                area of the sky when binned 2x2. When binned 1x1, four pixels are
                read, resulting in 2x the amount of read noise (sqrt(4)).

                The amount of signal does not increase when binning: the same number
                of photons are received by the 2x2 super pixel as the total received
                by the four underlying pixels.

                Regards,

                -Paul

                --- In ccd-newastro@yahoogroups.com, "Wodaski - Yahoo" <yahoo@...>
                wrote:
                >
                > That's not quite correct. Let me explain.
                >
                > When you bin 2x2, you are not reducing the read noise; you are
                increasing
                > the signal relative to the read noise by combining signal from
                multiple
                > pixels. So you get more signal, but the same read noise (one does
                of read
                > noise per read).
                >
                > Also, the benefit from this depends on the length of the exposure.
                If your
                > individual exposure times are reasonably optimal (that is, the
                read noise is
                > 1/15th or less of the total shot noise), then there is little to
                no benefit
                > from binning. SO the brighter your skies, the less improvement you
                will see
                > from this technique. The darker your skies, and the shorter your
                exposure
                > times, the more likely you are to see a benefit from binning.
                >
                > Ron Wodaski
                >
                > -----Original Message-----
                > From: ccd-newastro@yahoogroups.com [mailto:ccd-
                newastro@yahoogroups.com] On
                > Behalf Of Paul K
                > Sent: Thursday, October 04, 2007 6:00 AM
                > To: ccd-newastro@yahoogroups.com
                > Subject: [ccd-newastro] Re: Binning question
                >
                > Hi Eddy,
                >
                > Binning has one advantage over not binning: it reduces the read-
                out
                > noise of the camera. When taking filtered exposures of faint
                > objects, read-out noise can be the dominant noise in the image, so
                > it may be advantageous to bin RGB frames, especially in LRGB
                imaging.
                >
                > But, if your RGB exposure is long enough to overcome read-out
                > noise, or the object is bright enough to drown out this noise,
                > there's no good reason to bin (maybe just one: the images are
                > smaller and download faster <g>)
                >
                > If you bin 2x2, the image scale will be twice that of 1x1, i.e.,
                one-
                > half the resolution. To register and combine binned images with
                > unbinned you can manually resize the image to 200%, or use
                software
                > that can do this for you automatically (CCDStack, Registar, etc.)
                >
                > Regards,
                >
                > -Paul
                >
                >
                > --- In ccd-newastro@yahoogroups.com, "Eddy" <EddyMuriel@> wrote:
                > >
                > > Hi all,
                > >
                > > Could somebody, in a few words, explain me why one would use
                > binning?
                > >
                > > I see that some imagers are binning 2x2 the RGB channels but
                using
                > 1x1
                > > for the luminance. Others are using 1x1 for all the channels. To
                > me,
                > > both ways look the same.
                > >
                > > I understand that binning 2x2 will reduce exposure times. But
                that
                > is
                > > the only "advantage" I am seeing.
                > > When binning 2x2, the image scale will be different - if I
                > understood
                > > this correctly - than with 1x1.
                > > How do you convert or stack these? Do you have to change the
                image
                > > size before stacking?
                > >
                > > Thanks for any info,
                > > Eddy
                > >
                >
                >
                >
                >
                > Yahoo! Groups Links
                >




                Yahoo! Groups Links
              • Paul K
                Ah, yes. I see that we are in agreement :) Read noise is generated at a constant level per each pixel, no matter whether it s binned or not. In the binned
                Message 7 of 22 , Oct 4, 2007
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                  Ah, yes. I see that we are in agreement :)

                  Read noise is generated at a constant level per each pixel, no
                  matter whether it's binned or not. In the binned case, there are a
                  lot fewer pixels being read, so the signal-to-noise ratio goes up
                  significantly. But, as you point out, this is only important in the
                  case where read noise is dominant (which happens more frequently
                  with filtered exposures).

                  If read noise is a problem, the solution is to either bin, or to
                  stack more of, or to take longer unbinned exposures to increase S/N.

                  Regards,

                  -Paul

                  --- In ccd-newastro@yahoogroups.com, "Wodaski - Yahoo" <yahoo@...>
                  wrote:
                  >
                  > We are not really disagreeing. I didn't say there was more signal.
                  I said
                  > there was more signal _relative to the read noise_.
                  >
                  > My point was that the read noise is constant per read: you read
                  once, you
                  > get one dose of read noise. In that sense, the read noise does not
                  change.
                  > This is what I wanted to emphasize: that read noise is a constant,
                  one dose
                  > per read. Binning simply applies that noise to more than one pixel,
                  > increasing S/N.
                  >
                  > In the end, what is important with binning is that the _ratio_ of
                  signal to
                  > read noise is different.
                  >
                  > Note that it is important to remember that this is only important
                  if read
                  > noise is a significant component of total noise. If you have long
                  enough
                  > sub-exposures, then by definition read noise is a small part of
                  the total
                  > noise and binning will make very little difference in the signal
                  to noise
                  > ratio. (Shot noise changes with the signal; shot noise is the
                  square root of
                  > the signal.)
                  >
                  > Ron Wodaski
                  >
                  > -----Original Message-----
                  > From: ccd-newastro@yahoogroups.com [mailto:ccd-
                  newastro@yahoogroups.com] On
                  > Behalf Of Paul K
                  > Sent: Thursday, October 04, 2007 10:08 AM
                  > To: ccd-newastro@yahoogroups.com
                  > Subject: [ccd-newastro] Re: Binning question
                  >
                  > Sorry to disagree with you, Ron :)
                  >
                  > Binning does indeed reduce read noise: each binned super pixel is
                  > read only once, so the amount of read noise is halved for the same
                  > area of the sky when binned 2x2. When binned 1x1, four pixels are
                  > read, resulting in 2x the amount of read noise (sqrt(4)).
                  >
                  > The amount of signal does not increase when binning: the same
                  number
                  > of photons are received by the 2x2 super pixel as the total
                  received
                  > by the four underlying pixels.
                  >
                  > Regards,
                  >
                  > -Paul
                  >
                  > --- In ccd-newastro@yahoogroups.com, "Wodaski - Yahoo" <yahoo@>
                  > wrote:
                  > >
                  > > That's not quite correct. Let me explain.
                  > >
                  > > When you bin 2x2, you are not reducing the read noise; you are
                  > increasing
                  > > the signal relative to the read noise by combining signal from
                  > multiple
                  > > pixels. So you get more signal, but the same read noise (one
                  does
                  > of read
                  > > noise per read).
                  > >
                  > > Also, the benefit from this depends on the length of the
                  exposure.
                  > If your
                  > > individual exposure times are reasonably optimal (that is, the
                  > read noise is
                  > > 1/15th or less of the total shot noise), then there is little to
                  > no benefit
                  > > from binning. SO the brighter your skies, the less improvement
                  you
                  > will see
                  > > from this technique. The darker your skies, and the shorter your
                  > exposure
                  > > times, the more likely you are to see a benefit from binning.
                  > >
                  > > Ron Wodaski
                  > >
                  > > -----Original Message-----
                  > > From: ccd-newastro@yahoogroups.com [mailto:ccd-
                  > newastro@yahoogroups.com] On
                  > > Behalf Of Paul K
                  > > Sent: Thursday, October 04, 2007 6:00 AM
                  > > To: ccd-newastro@yahoogroups.com
                  > > Subject: [ccd-newastro] Re: Binning question
                  > >
                  > > Hi Eddy,
                  > >
                  > > Binning has one advantage over not binning: it reduces the read-
                  > out
                  > > noise of the camera. When taking filtered exposures of faint
                  > > objects, read-out noise can be the dominant noise in the image,
                  so
                  > > it may be advantageous to bin RGB frames, especially in LRGB
                  > imaging.
                  > >
                  > > But, if your RGB exposure is long enough to overcome read-out
                  > > noise, or the object is bright enough to drown out this noise,
                  > > there's no good reason to bin (maybe just one: the images are
                  > > smaller and download faster <g>)
                  > >
                  > > If you bin 2x2, the image scale will be twice that of 1x1, i.e.,
                  > one-
                  > > half the resolution. To register and combine binned images with
                  > > unbinned you can manually resize the image to 200%, or use
                  > software
                  > > that can do this for you automatically (CCDStack, Registar, etc.)
                  > >
                  > > Regards,
                  > >
                  > > -Paul
                  > >
                  > >
                  > > --- In ccd-newastro@yahoogroups.com, "Eddy" <EddyMuriel@> wrote:
                  > > >
                  > > > Hi all,
                  > > >
                  > > > Could somebody, in a few words, explain me why one would use
                  > > binning?
                  > > >
                  > > > I see that some imagers are binning 2x2 the RGB channels but
                  > using
                  > > 1x1
                  > > > for the luminance. Others are using 1x1 for all the channels.
                  To
                  > > me,
                  > > > both ways look the same.
                  > > >
                  > > > I understand that binning 2x2 will reduce exposure times. But
                  > that
                  > > is
                  > > > the only "advantage" I am seeing.
                  > > > When binning 2x2, the image scale will be different - if I
                  > > understood
                  > > > this correctly - than with 1x1.
                  > > > How do you convert or stack these? Do you have to change the
                  > image
                  > > > size before stacking?
                  > > >
                  > > > Thanks for any info,
                  > > > Eddy
                  > > >
                  > >
                  > >
                  > >
                  > >
                  > > Yahoo! Groups Links
                  > >
                  >
                  >
                  >
                  >
                  > Yahoo! Groups Links
                  >
                • Mike Dodd
                  ... I recently tried taking the color frames unbinned; the total exposure was _very_long, and the color subs were quite noisy. I ve since decided that unbinned
                  Message 8 of 22 , Oct 4, 2007
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                    Eddy wrote:
                    > I do have time (I am retired), so I could skip the binning technique,
                    > but the main problem is that the weather is not always cooperative...

                    I recently tried taking the color frames unbinned; the total exposure
                    was _very_long, and the color subs were quite noisy. I've since
                    decided that unbinned color isn't a good choice for me.

                    --- Mike

                    --

                    Mike Dodd
                    Montpelier, VA USA
                    http://astronomy.mdodd.com
                  • Randy Nulman
                    Hi All, Also note that even with TV transmissions, the color is blurred with the monochrome data providing the detail. I don t know how, or if, this has
                    Message 9 of 22 , Oct 4, 2007
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                      Hi All,

                      Also note that even with TV transmissions, the color is "blurred"
                      with the monochrome data providing the detail. I don't know how, or
                      if, this has changed with HD signals...but this was the norm.

                      Randy Nulman
                      http://www.nulman.darkhorizons.org


                      --- In ccd-newastro@yahoogroups.com, Mike Dodd <mike_dodd@...> wrote:
                      >
                      > Eddy wrote:
                      > > I do have time (I am retired), so I could skip the binning
                      technique,
                      > > but the main problem is that the weather is not always
                      cooperative...
                      >
                      > I recently tried taking the color frames unbinned; the total
                      exposure
                      > was _very_long, and the color subs were quite noisy. I've since
                      > decided that unbinned color isn't a good choice for me.
                      >
                      > --- Mike
                      >
                      > --
                      >
                      > Mike Dodd
                      > Montpelier, VA USA
                      > http://astronomy.mdodd.com
                      >
                    • wt5l_jon
                      Hi Eddy, Most of the advantages of binning have been mentioned. One of the disadvantages is the need to capture and keep a separate set of calibration frames
                      Message 10 of 22 , Oct 4, 2007
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                        Hi Eddy,

                        Most of the advantages of binning have been mentioned. One of the
                        disadvantages is the need to capture and keep a separate set of
                        calibration frames (darks) for each binning that you use. Usually
                        this is not considered a problem since these can be captured during
                        poor imaging conditions and then reused. Just another level of
                        complexity...

                        Jon


                        --- In ccd-newastro@yahoogroups.com, "Eddy" <EddyMuriel@...> wrote:
                        >
                        > Hi all,
                        >
                        > Could somebody, in a few words, explain me why one would use binning?
                        >
                        > I see that some imagers are binning 2x2 the RGB channels but using 1x1
                        > for the luminance. Others are using 1x1 for all the channels. To me,
                        > both ways look the same.
                        >
                        > I understand that binning 2x2 will reduce exposure times. But that is
                        > the only "advantage" I am seeing.
                        > When binning 2x2, the image scale will be different - if I understood
                        > this correctly - than with 1x1.
                        > How do you convert or stack these? Do you have to change the image
                        > size before stacking?
                        >
                        > Thanks for any info,
                        > Eddy
                        >
                      • sc02492
                        Eddy, I m coming in on this discussion fashionably late . Here is a little write up on binning that I put together on my website last year:
                        Message 11 of 22 , Oct 4, 2007
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                          Eddy, I'm coming in on this discussion fashionably late <g>. Here is
                          a little write up on binning that I put together on my website last year:

                          http://www.starrywonders.com/binning.html

                          If you don't like math (not really as complicated as it looks), then
                          just scroll down to the "bottom line" summary.


                          Steve

                          Steve Cannistra
                          http://www.starrywonders.com

                          --- In ccd-newastro@yahoogroups.com, "Eddy" <EddyMuriel@...> wrote:
                          >
                          > Hi all,
                          >
                          > Could somebody, in a few words, explain me why one would use binning?
                          >
                          > I see that some imagers are binning 2x2 the RGB channels but using 1x1
                          > for the luminance. Others are using 1x1 for all the channels. To me,
                          > both ways look the same.
                          >
                          > I understand that binning 2x2 will reduce exposure times. But that is
                          > the only "advantage" I am seeing.
                          > When binning 2x2, the image scale will be different - if I understood
                          > this correctly - than with 1x1.
                          > How do you convert or stack these? Do you have to change the image
                          > size before stacking?
                          >
                          > Thanks for any info,
                          > Eddy
                          >
                        • Neil Fleming
                          I tried binning a few times, and never liked the result. Too big a compromise on the overall result. I know that many swear by this approach, though. ...
                          Message 12 of 22 , Oct 4, 2007
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                            I tried binning a few times, and never liked the
                            result. Too big a compromise on the overall result.
                            I know that many swear by this approach, though.

                            ...Neil

                            --- Eddy <EddyMuriel@...> wrote:

                            > Ok, Thank you, Ron. I am understanding it now and I
                            > guess I have to
                            > try the technique so see for myself.
                            >
                            > I do have time (I am retired), so I could skip the
                            > binning technique,
                            > but the main problem is that the weather is not
                            > always cooperative...
                            > I guess this is also a reason for binning. Unless
                            > somebody could wait
                            > a couple of months before having a nice picture.
                            >
                            > Thank you,
                            > Eddy
                            >
                            >


                            www.flemingastrophotography.com
                            Direct from Boston - brilliant diamonds in pea soup
                          • Eddy
                            Thank you all for your replies. Steve, nice write up. Thanks! Jon mentioned you need a new set of darks, but if I understood everything up to now, you don t
                            Message 13 of 22 , Oct 5, 2007
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                              Thank you all for your replies.

                              Steve, nice write up. Thanks!

                              Jon mentioned you need a new set of darks, but if I understood
                              everything up to now, you don't need to take new flats when binning,
                              right? The image train remains the same and binning doesn't change
                              anything on this, correct?

                              Eddy
                            • wt5l_jon
                              Eddy, Correct, you only need the dark and bias (if you use them) frames for each binning you use. You can take one set of unbinned flats to serve all binned
                              Message 14 of 22 , Oct 5, 2007
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                                Eddy,

                                Correct, you only need the dark and bias (if you use them) frames for
                                each binning you use. You can take one set of unbinned flats to serve
                                all binned or unbinned images.

                                Jon

                                --- In ccd-newastro@yahoogroups.com, "Eddy" <EddyMuriel@...> wrote:
                                >
                                > Thank you all for your replies.
                                >
                                > Steve, nice write up. Thanks!
                                >
                                > Jon mentioned you need a new set of darks, but if I understood
                                > everything up to now, you don't need to take new flats when binning,
                                > right? The image train remains the same and binning doesn't change
                                > anything on this, correct?
                                >
                                > Eddy
                                >
                              • Eddy
                                ... Thank you for confirming this, Jon. Eddy
                                Message 15 of 22 , Oct 5, 2007
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                                  --- In ccd-newastro@yahoogroups.com, "wt5l_jon" <jonolson@...> wrote:
                                  >
                                  > Eddy,
                                  >
                                  > Correct, you only need the dark and bias (if you use them) frames for
                                  > each binning you use. You can take one set of unbinned flats to serve
                                  > all binned or unbinned images.
                                  >
                                  Thank you for confirming this, Jon.

                                  Eddy
                                • Donald Waid
                                  Eddy, My understanding is you can use the unbinned flats to reduce binned frames but you have to rescale the flats to the binned size first. If I am
                                  Message 16 of 22 , Oct 5, 2007
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                                    Eddy,

                                    My understanding is you can use the unbinned flats to reduce binned frames
                                    but you have to "rescale" the flats to the binned size first. If I am
                                    incorrect on this, someone please let me know.

                                    Don Waid

                                    ----- Original Message -----
                                    From: "Eddy" <EddyMuriel@...>
                                    To: <ccd-newastro@yahoogroups.com>
                                    Sent: Friday, October 05, 2007 4:13 AM
                                    Subject: [ccd-newastro] Re: Binning question


                                    > Thank you all for your replies.
                                    >
                                    > Steve, nice write up. Thanks!
                                    >
                                    > Jon mentioned you need a new set of darks, but if I understood
                                    > everything up to now, you don't need to take new flats when binning,
                                    > right? The image train remains the same and binning doesn't change
                                    > anything on this, correct?
                                    >
                                    > Eddy
                                    >
                                    >
                                    >
                                    > Yahoo! Groups Links
                                    >
                                    >
                                    >
                                  • Wodaski - Yahoo
                                    I ve always had good success by re-sizing my 1x1 flats for binned images. You usually need to change the bin setting in the FITS header when you do this,
                                    Message 17 of 22 , Oct 5, 2007
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                                      I've always had good success by re-sizing my 1x1 flats for binned images.

                                      You usually need to change the bin setting in the FITS header when you do
                                      this, unless the software you are using (e.g., MaxIm DL) will do it for you.
                                      (Otherwise, the flat will not be recognized for what it now is by the
                                      automated features of the calibration process in said software.)

                                      Ron W


                                      -----Original Message-----
                                      From: ccd-newastro@yahoogroups.com [mailto:ccd-newastro@yahoogroups.com] On
                                      Behalf Of Eddy
                                      Sent: Friday, October 05, 2007 2:14 AM
                                      To: ccd-newastro@yahoogroups.com
                                      Subject: [ccd-newastro] Re: Binning question

                                      Thank you all for your replies.

                                      Steve, nice write up. Thanks!

                                      Jon mentioned you need a new set of darks, but if I understood
                                      everything up to now, you don't need to take new flats when binning,
                                      right? The image train remains the same and binning doesn't change
                                      anything on this, correct?

                                      Eddy



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