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RE: [ccd-newastro] Binning lum. exposures?

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  • Eddie Trimarchi
    Randy, If you have an ST8, then you can still get a decent size image by binning 2x2. I have an ST7 and 2x2 binning just gives to small an image. Might as well
    Message 1 of 7 , Mar 9, 2001
      Randy,
      If you have an ST8, then you can still get a decent size image by binning
      2x2. I have an ST7 and 2x2 binning just gives to small an image. Might as
      well be using an ST6.

      I prefer to use the unbinned ST7. My skies arn't that great but with the
      AO7, it's great. Personally, if I had an ST8, I would hate having to bin it.
      It's a personal thing really :)

      Nothing wrong with your logic though. If your skies are 4" pp, then you will
      not get good images at 1.17"pp. Unless maybe you take reaallly long
      exposures but then you probably have loads of sky glow too, which may
      adversely affect binned images too depending on the severity of the glow.

      If I were you, I'd get an AO7!

      Regards,

      Eddie Trimarchi
      ~~~~~~~~~~~~~~~
      http://users.fan.net.au/~eddiet

      >-----Original Message-----
      >From: Randy Nulman [mailto:rjnulman@...]
      >Sent: Saturday, March 10, 2001 4:52 PM
      >To: ccd-newastro@yahoogroups.com
      >Subject: [ccd-newastro] Binning lum. exposures?
      >
      >
      >Hi,
      >Hopefully, next week will be clear and I can start imaging instead of
      >sitting here asking stupid questions. So I have one last question
      >before I get back to the camera:
      >I recently moved to slightly darker skies, but the trade off is worse
      >seeing conditions. My best guest is that I'm dealing with 4 arc
      >second stars on an average night.
      >
      >I notice that almost all images I see use unbinned Lum. exposures.
      >My question is that since I'm imaging at 1575mm (ST8) which produces
      >1.17 arc. sec. per pixel...what do I gain by not binning when I have
      >4 arc. sec. skies? Seems to me (unless I get a great night), I
      >should bin and take advantage of the increased sensitivity. I don't
      >see where not binning will increase resolution.. due to the sky
      >limitations. (If I'm correct, I suspect that a lot of people are
      >dealing with similar type skies, and wasting sensitivity without
      >realizing any gain).
      >
      >Anything wrong with this logic?
      >
      >Thanks,
      >Randy
      >
      >
      >
      >
      >To unsubscribe from this group, send an email to:
      >ccd-newastro-unsubscribe@egroups.com
      >
      >
      >
      >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
      >
      >
      >
    • Randy Nulman
      Hi Eddie, I understand your point. The skies are darker here, so I m not sure that sky glow will be as bad as my previous location. Also, I can always filter
      Message 2 of 7 , Mar 9, 2001
        Hi Eddie,
        I understand your point.

        The skies are darker here, so I'm not sure that sky glow will be as
        bad as my previous location. Also, I can always filter it out.

        As for the AO7, you're the second person to suggest it...Guess the
        spending never ends in this hobby!!!

        Thanks,
        Randy

        --- In ccd-newastro@y..., "Eddie Trimarchi" <eddiet@b...> wrote:
        > Randy,
        > If you have an ST8, then you can still get a decent size image by
        binning
        > 2x2. I have an ST7 and 2x2 binning just gives to small an image.
        Might as
        > well be using an ST6.
        >
        > I prefer to use the unbinned ST7. My skies arn't that great but
        with the
        > AO7, it's great. Personally, if I had an ST8, I would hate having
        to bin it.
        > It's a personal thing really :)
        >
        > Nothing wrong with your logic though. If your skies are 4" pp, then
        you will
        > not get good images at 1.17"pp. Unless maybe you take reaallly long
        > exposures but then you probably have loads of sky glow too, which
        may
        > adversely affect binned images too depending on the severity of the
        glow.
        >
        > If I were you, I'd get an AO7!
        >
        > Regards,
        >
        > Eddie Trimarchi
        > ~~~~~~~~~~~~~~~
        > http://users.fan.net.au/~eddiet
        >
        > >-----Original Message-----
        > >From: Randy Nulman [mailto:rjnulman@w...]
        > >Sent: Saturday, March 10, 2001 4:52 PM
        > >To: ccd-newastro@y...
        > >Subject: [ccd-newastro] Binning lum. exposures?
        > >
        > >
        > >Hi,
        > >Hopefully, next week will be clear and I can start imaging instead
        of
        > >sitting here asking stupid questions. So I have one last question
        > >before I get back to the camera:
        > >I recently moved to slightly darker skies, but the trade off is
        worse
        > >seeing conditions. My best guest is that I'm dealing with 4 arc
        > >second stars on an average night.
        > >
        > >I notice that almost all images I see use unbinned Lum. exposures.
        > >My question is that since I'm imaging at 1575mm (ST8) which
        produces
        > >1.17 arc. sec. per pixel...what do I gain by not binning when I
        have
        > >4 arc. sec. skies? Seems to me (unless I get a great night), I
        > >should bin and take advantage of the increased sensitivity. I
        don't
        > >see where not binning will increase resolution.. due to the sky
        > >limitations. (If I'm correct, I suspect that a lot of people are
        > >dealing with similar type skies, and wasting sensitivity without
        > >realizing any gain).
        > >
        > >Anything wrong with this logic?
        > >
        > >Thanks,
        > >Randy
        > >
        > >
        > >
        > >
        > >To unsubscribe from this group, send an email to:
        > >ccd-newastro-unsubscribe@egroups.com
        > >
        > >
        > >
        > >Your use of Yahoo! Groups is subject to
        http://docs.yahoo.com/info/terms/
        > >
        > >
        > >
      • Eddie Trimarchi
        Randy, ... Too true! I have made my final astro-related purchase several times over :) Actually, it was very, very difficult to convince myself that I could
        Message 3 of 7 , Mar 10, 2001
          Randy,

          >As for the AO7, you're the second person to suggest it...Guess the
          >spending never ends in this hobby!!!

          Too true! I have made my final astro-related purchase several times over :)
          Actually, it was very, very difficult to convince myself that I could not
          afford an ST8. I'm glad I did though, because I really couldn't!

          As for the AO7 it is really a great device. It gets you as close as possible
          to acheiving the best resolution you can with your scope/camera. It can deal
          with most tracking errors, minor wind gusts, mirror shift/flop, etc.

          With a good guidestar and corrections between 10 and 20 Hz, you should not
          need to bin and will be getting the resolution you deserve from the great
          camera you paid for. That's my view anyway!

          Regards,

          Eddie Trimarchi
          ~~~~~~~~~~~~~~~
          http://users.fan.net.au/~eddiet

          >-----Original Message-----
          >From: Randy Nulman [mailto:rjnulman@...]
          >Sent: Saturday, March 10, 2001 5:54 PM
          >To: ccd-newastro@yahoogroups.com
          >Subject: [ccd-newastro] Re: Binning lum. exposures?
          >
          >
          >
          >Hi Eddie,
          >I understand your point.
          >
          >The skies are darker here, so I'm not sure that sky glow will be as
          >bad as my previous location. Also, I can always filter it out.
          >
          >As for the AO7, you're the second person to suggest it...Guess the
          >spending never ends in this hobby!!!
          >
          >Thanks,
          >Randy
          >
          >--- In ccd-newastro@y..., "Eddie Trimarchi" <eddiet@b...> wrote:
          >> Randy,
          >> If you have an ST8, then you can still get a decent size image by
          >binning
          >> 2x2. I have an ST7 and 2x2 binning just gives to small an image.
          >Might as
          >> well be using an ST6.
          >>
          >> I prefer to use the unbinned ST7. My skies arn't that great but
          >with the
          >> AO7, it's great. Personally, if I had an ST8, I would hate having
          >to bin it.
          >> It's a personal thing really :)
          >>
          >> Nothing wrong with your logic though. If your skies are 4" pp, then
          >you will
          >> not get good images at 1.17"pp. Unless maybe you take reaallly long
          >> exposures but then you probably have loads of sky glow too, which
          >may
          >> adversely affect binned images too depending on the severity of the
          >glow.
          >>
          >> If I were you, I'd get an AO7!
          >>
          >> Regards,
          >>
          >> Eddie Trimarchi
          >> ~~~~~~~~~~~~~~~
          >> http://users.fan.net.au/~eddiet
          >>
          >> >-----Original Message-----
          >> >From: Randy Nulman [mailto:rjnulman@w...]
          >> >Sent: Saturday, March 10, 2001 4:52 PM
          >> >To: ccd-newastro@y...
          >> >Subject: [ccd-newastro] Binning lum. exposures?
          >> >
          >> >
          >> >Hi,
          >> >Hopefully, next week will be clear and I can start imaging instead
          >of
          >> >sitting here asking stupid questions. So I have one last question
          >> >before I get back to the camera:
          >> >I recently moved to slightly darker skies, but the trade off is
          >worse
          >> >seeing conditions. My best guest is that I'm dealing with 4 arc
          >> >second stars on an average night.
          >> >
          >> >I notice that almost all images I see use unbinned Lum. exposures.
          >> >My question is that since I'm imaging at 1575mm (ST8) which
          >produces
          >> >1.17 arc. sec. per pixel...what do I gain by not binning when I
          >have
          >> >4 arc. sec. skies? Seems to me (unless I get a great night), I
          >> >should bin and take advantage of the increased sensitivity. I
          >don't
          >> >see where not binning will increase resolution.. due to the sky
          >> >limitations. (If I'm correct, I suspect that a lot of people are
          >> >dealing with similar type skies, and wasting sensitivity without
          >> >realizing any gain).
          >> >
          >> >Anything wrong with this logic?
          >> >
          >> >Thanks,
          >> >Randy
          >> >
          >> >
          >> >
          >> >
          >> >To unsubscribe from this group, send an email to:
          >> >ccd-newastro-unsubscribe@egroups.com
          >> >
          >> >
          >> >
          >> >Your use of Yahoo! Groups is subject to
          >http://docs.yahoo.com/info/terms/
          >> >
          >> >
          >> >
          >
          >
          >
          >To unsubscribe from this group, send an email to:
          >ccd-newastro-unsubscribe@egroups.com
          >
          >
          >
          >Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
          >
          >
          >
        • Ron Wodaski
          I don t see any flaw in your logic. You can easily test your situation by taking matched binned and unbinned exposures to see what difference you get. Ron
          Message 4 of 7 , Mar 10, 2001
            I don't see any flaw in your logic. You can easily test your situation by
            taking matched binned and unbinned exposures to see what difference you get.

            Ron Wodaski
            The New CCD Astronomy
            http://www.newastro.com

            -----Original Message-----
            From: Randy Nulman [mailto:rjnulman@...]
            Sent: Friday, March 09, 2001 10:52 PM
            To: ccd-newastro@yahoogroups.com
            Subject: [ccd-newastro] Binning lum. exposures?


            Hi,
            Hopefully, next week will be clear and I can start imaging instead of
            sitting here asking stupid questions. So I have one last question
            before I get back to the camera:
            I recently moved to slightly darker skies, but the trade off is worse
            seeing conditions. My best guest is that I'm dealing with 4 arc
            second stars on an average night.

            I notice that almost all images I see use unbinned Lum. exposures.
            My question is that since I'm imaging at 1575mm (ST8) which produces
            1.17 arc. sec. per pixel...what do I gain by not binning when I have
            4 arc. sec. skies? Seems to me (unless I get a great night), I
            should bin and take advantage of the increased sensitivity. I don't
            see where not binning will increase resolution.. due to the sky
            limitations. (If I'm correct, I suspect that a lot of people are
            dealing with similar type skies, and wasting sensitivity without
            realizing any gain).

            Anything wrong with this logic?

            Thanks,
            Randy




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            ccd-newastro-unsubscribe@egroups.com



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          • Mark & Shauna
            Randy, the only issue that was not covered in your and Eddies exchange is that while you rseeing may average 4 you probably have several instances for brief
            Message 5 of 7 , Mar 10, 2001
              Randy, the only issue that was not covered in your and Eddies exchange is that while you rseeing may average 4" you probably have several instances for brief periods of time where it gets much better. These can be for an instant or can last for small durations of time. If you do opt to bin you lose the ability to capture data that was imaged in these instances of good seeing. If your skies are consistently 4" then your philosophy would be correct however I would assume that you have some short intervals of better seeing on most of your nights.
               
              Just my two cents....
              -----Original Message-----
              From: Randy Nulman [mailto:rjnulman@...]
              Sent: 10 March, 2001 1:52 AM
              To: ccd-newastro@yahoogroups.com
              Subject: [ccd-newastro] Binning lum. exposures?

              Hi,
              Hopefully, next week will be clear and I can start imaging instead of
              sitting here asking stupid questions. So I have one last question
              before I get back to the camera:
              I recently moved to slightly darker skies, but the trade off is worse
              seeing conditions.  My best guest is that I'm dealing with 4 arc
              second stars on an average night. 

              I notice that almost all images I see use unbinned Lum. exposures.
              My question is that since I'm imaging at 1575mm (ST8) which produces
              1.17 arc. sec. per pixel...what do I gain by not binning when I have
              4 arc. sec. skies?  Seems to me (unless I get a great night), I
              should bin and take advantage of the increased sensitivity.  I don't
              see where not binning will increase resolution.. due to the sky
              limitations.  (If I'm correct, I suspect that a lot of people are
              dealing with similar type skies, and wasting sensitivity without
              realizing any gain).

              Anything wrong with this logic?

              Thanks,
              Randy




              To unsubscribe from this group, send an email to:
              ccd-newastro-unsubscribe@egroups.com



              Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
            • Ron Wodaski
              One way to judge this is to determine the FWHM (full width at half maximum) value for your star images. Not all camera control or image editing software allows
              Message 6 of 7 , Mar 10, 2001
                One way to judge this is to determine the FWHM (full width at half maximum) value for your star images. Not all camera control or image editing software allows you to do this; Mira and Maxim DL do. If your FWHM is > 4pixels, then you know for sure that binning 2x2 makes sense. But if it gets below 3, then you might consider some 1x1 binning. The actual crossover point depends on your patience for long exposures. <g>
                 
                You should always test FWHM unbinned, so that you get the most accurate measurement.
                 

                Ron Wodaski
                The New CCD Astronomy
                http://www.newastro.com

                -----Original Message-----
                From: Mark & Shauna [mailto:grolleg@...]
                Sent: Saturday, March 10, 2001 1:26 PM
                To: ccd-newastro@yahoogroups.com
                Subject: RE: [ccd-newastro] Binning lum. exposures?

                Randy, the only issue that was not covered in your and Eddies exchange is that while you rseeing may average 4" you probably have several instances for brief periods of time where it gets much better. These can be for an instant or can last for small durations of time. If you do opt to bin you lose the ability to capture data that was imaged in these instances of good seeing. If your skies are consistently 4" then your philosophy would be correct however I would assume that you have some short intervals of better seeing on most of your nights.
                 
                Just my two cents....
                -----Original Message-----
                From: Randy Nulman [mailto:rjnulman@...]
                Sent: 10 March, 2001 1:52 AM
                To: ccd-newastro@yahoogroups.com
                Subject: [ccd-newastro] Binning lum. exposures?

                Hi,
                Hopefully, next week will be clear and I can start imaging instead of
                sitting here asking stupid questions. So I have one last question
                before I get back to the camera:
                I recently moved to slightly darker skies, but the trade off is worse
                seeing conditions.  My best guest is that I'm dealing with 4 arc
                second stars on an average night. 

                I notice that almost all images I see use unbinned Lum. exposures.
                My question is that since I'm imaging at 1575mm (ST8) which produces
                1.17 arc. sec. per pixel...what do I gain by not binning when I have
                4 arc. sec. skies?  Seems to me (unless I get a great night), I
                should bin and take advantage of the increased sensitivity.  I don't
                see where not binning will increase resolution.. due to the sky
                limitations.  (If I'm correct, I suspect that a lot of people are
                dealing with similar type skies, and wasting sensitivity without
                realizing any gain).

                Anything wrong with this logic?

                Thanks,
                Randy




                To unsubscribe from this group, send an email to:
                ccd-newastro-unsubscribe@egroups.com



                Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.


                To unsubscribe from this group, send an email to:
                ccd-newastro-unsubscribe@egroups.com



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