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Re: [Stellarvue] M27 in Hubble Colors

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  • David Elosser
    Jim, that s a great photo of the Dumbbell. Thanks for posting it. What do you mean by Hubble Colors? David E ... From: actx03 To:
    Message 1 of 6 , Jul 1, 2007
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      Jim, that's a great photo of the Dumbbell. Thanks for posting it. What do
      you mean by "Hubble Colors?"

      David E
      ----- Original Message -----
      From: "actx03" <powell-jr@...>
      To: <Stellarvue@yahoogroups.com>
      Sent: Saturday, June 30, 2007 8:49 PM
      Subject: [Stellarvue] M27 in Hubble Colors


      > Hello to Everyone, I just posted my first attempt at imaging in
      > narrowband using the Hubble Map format in the Dr. Jim P folder. M27
      > is low in the East and the city light dome so it seemed a good time to
      > try it. My question is about the SII channel. I do not yet have an
      > SII filter, although hopes are high for my upcoming birthday. I opted
      > to use 80 minutes of RED taken in 10 minute subs last week as a
      > substitute. I also got only two 20 minute Ha shots before clouds
      > ended the night. The OIII line was 100 minutes at 20 minutes each.
      > Should I try some other combination that will look better? I will add
      > to the Ha line tonight if things hold. I know some have used only Ha
      > and OIII. Also, can anyone suggest other targets for this type of
      > imaging that are north of about -20 degrees South. The area around
      > Cygnus seems promising, but limited to mainly red colored objects.
      > Any help is appreciated and comments on processing are also welcomed.
      > Drs. Jim and Linda Powell
      > SV-102 APO doublet
      > SV-102DN
      > Nighthawk
      > SV-145 ON ORDER!
      >
      >
      >
      > To unsubscribe, send an email to:
      > Stellarvue-unsubscribe@egroups.com.
      >
      > Remember: the archives are a rich source of information and they are
      > searchable.
      >
      >
      > Yahoo! Groups Links
      >
      >
      >
      >
      >
    • david james
      Hey Jim, I like your Dumbell image. Thanks for sharing. By Hubble colors do you mean using three different color exposures? Or is it another method you are
      Message 2 of 6 , Jul 1, 2007
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        Hey Jim, I like your Dumbell image. Thanks for sharing. By Hubble colors do you mean using three different color exposures? Or is it another method you are using?

        David J



        ----- Original Message ----
        From: David Elosser <pde444@...>
        To: Stellarvue@yahoogroups.com
        Sent: Sunday, July 1, 2007 5:05:45 AM
        Subject: Re: [Stellarvue] M27 in Hubble Colors

        Jim, that's a great photo of the Dumbbell. Thanks for posting it. What do
        you mean by "Hubble Colors?"

        David E
        ----- Original Message -----
        From: "actx03" <powell-jr@actx. edu>
        To: <Stellarvue@yahoogro ups.com>
        Sent: Saturday, June 30, 2007 8:49 PM
        Subject: [Stellarvue] M27 in Hubble Colors

        > Hello to Everyone, I just posted my first attempt at imaging in
        > narrowband using the Hubble Map format in the Dr. Jim P folder. M27
        > is low in the East and the city light dome so it seemed a good time to
        > try it. My question is about the SII channel. I do not yet have an
        > SII filter, although hopes are high for my upcoming birthday. I opted
        > to use 80 minutes of RED taken in 10 minute subs last week as a
        > substitute. I also got only two 20 minute Ha shots before clouds
        > ended the night. The OIII line was 100 minutes at 20 minutes each.
        > Should I try some other combination that will look better? I will add
        > to the Ha line tonight if things hold. I know some have used only Ha
        > and OIII. Also, can anyone suggest other targets for this type of
        > imaging that are north of about -20 degrees South. The area around
        > Cygnus seems promising, but limited to mainly red colored objects.
        > Any help is appreciated and comments on processing are also welcomed.
        > Drs. Jim and Linda Powell
        > SV-102 APO doublet
        > SV-102DN
        > Nighthawk
        > SV-145 ON ORDER!
        >
        >
        >
        > To unsubscribe, send an email to:
        > Stellarvue-unsubscr ibe@egroups. com.
        >
        > Remember: the archives are a rich source of information and they are
        > searchable.
        >
        >
        > Yahoo! Groups Links
        >
        >
        >
        >
        >




        [Non-text portions of this message have been removed]
      • Jon Talbot
        Hi Jim, Given your limited exposure times you created a nice color composite using a partial Hubble pallet. It was a good idea to include red in place of
        Message 3 of 6 , Jul 1, 2007
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          Hi Jim,

          Given your limited exposure times you created a nice color composite using a partial
          "Hubble" pallet. It was a good idea to include red in place of SII. A SII filter would be
          useful but let me give you some advice up front. Imaging with an SII filter will require
          "long" exposures and lots of them. In reality all the NB filters require this on most
          everthing except the brightest objects. What I mean by long is 20min per exposure and
          5-10 hrs of total exposure time. You can get by with shorter exposures as you have
          shown on bright objects since Ha and OIII are strong emitters in planetarys. Many objects
          are very weak in suphur emission and to get the signal you need lots of exposures. The
          idea behind NB imaging is to seperated the various emission bands and assign colors to
          them. At first it looks wierd to see Ha expressed as green. Many people dont like it.
          Fortunately you are in control assigning whatever color you like.

          It tough to get images that have the colors of the Hubble pallet. Colors meaning that the
          SII really shows up as red and the Ha is kind of an orange color. That orange comes from
          about an equal mix of Red (SII) and Green (Ha). Usually Ha dominates the emission so
          tricks are needed in processing the data to lessen the Ha contribution and increasing the
          SII emission. Problem here is you need a very clean SII master frame which is what takes
          an extraordinary amount of imaging time.

          For those who wonder what the "Hubble pallet" is: Color are assigned based on
          wavelength. Red goes to the shortest wavelenth (SII), Green to the middle wavelength (Ha)
          and blue to the longest (OIII).

          Jon Talbot

          --- In Stellarvue@yahoogroups.com, "actx03" <powell-jr@...> wrote:
          >
          > Hello to Everyone, I just posted my first attempt at imaging in
          > narrowband using the Hubble Map format in the Dr. Jim P folder. M27
          > is low in the East and the city light dome so it seemed a good time to
          > try it. My question is about the SII channel. I do not yet have an
          > SII filter, although hopes are high for my upcoming birthday. I opted
          > to use 80 minutes of RED taken in 10 minute subs last week as a
          > substitute. I also got only two 20 minute Ha shots before clouds
          > ended the night. The OIII line was 100 minutes at 20 minutes each.
          > Should I try some other combination that will look better? I will add
          > to the Ha line tonight if things hold. I know some have used only Ha
          > and OIII. Also, can anyone suggest other targets for this type of
          > imaging that are north of about -20 degrees South. The area around
          > Cygnus seems promising, but limited to mainly red colored objects.
          > Any help is appreciated and comments on processing are also welcomed.
          > Drs. Jim and Linda Powell
          > SV-102 APO doublet
          > SV-102DN
          > Nighthawk
          > SV-145 ON ORDER!
          >
        • Philip Good
          Looks good Jim. I d like to see a larger scale with less compression. This is a great time of year for narrowband imaging. There are a lot of Narrowband
          Message 4 of 6 , Jul 1, 2007
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            Looks good Jim. I'd like to see a larger scale with less compression.

            This is a great time of year for narrowband imaging. There are a lot
            of Narrowband targets coming up now, particularly in the Cygnus area.
            The Veil East and West have nice distinct lines. Just above your
            limit are the Eagle and the Swan north of Sagittarius.

            Phil


            On Jun 30, 2007, at 6:49 PM, actx03 wrote:

            > Hello to Everyone, I just posted my first attempt at imaging in
            > narrowband using the Hubble Map format in the Dr. Jim P folder. M27
            > is low in the East and the city light dome so it seemed a good time to
            > try it. My question is about the SII channel. I do not yet have an
            > SII filter, although hopes are high for my upcoming birthday. I opted
            > to use 80 minutes of RED taken in 10 minute subs last week as a
            > substitute. I also got only two 20 minute Ha shots before clouds
            > ended the night. The OIII line was 100 minutes at 20 minutes each.
            > Should I try some other combination that will look better? I will add
            > to the Ha line tonight if things hold. I know some have used only Ha
            > and OIII. Also, can anyone suggest other targets for this type of
            > imaging that are north of about -20 degrees South. The area around
            > Cygnus seems promising, but limited to mainly red colored objects.
            > Any help is appreciated and comments on processing are also welcomed.
            > Drs. Jim and Linda Powell
            > SV-102 APO doublet
            > SV-102DN
            > Nighthawk
            > SV-145 ON ORDER!
            >
            >
            >



            [Non-text portions of this message have been removed]
          • Matt Thomas
            Jim, That is an excellent first narrowband image. With narrowband imaging, I would say pretty much anything goes. You do what you think looks good. There are
            Message 5 of 6 , Jul 3, 2007
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              Jim,

              That is an excellent first narrowband image.

              With narrowband imaging, I would say pretty much anything goes. You
              do what you think looks good.

              There are lots of opinions out there on what to do, but the advantage
              of narrowband is that there are no preconceived notions about what
              color something is supposed to be or what it is supposed to look like.

              In terms of what targets, just about any Ha (red) emission nebula
              would be good for narrowband. Stay away from reflection (blue) and
              dark nebula. These will probably not yield much in narrowband.

              -Matt Thomas
              http://www.astromatt.com/
              CCD Commander: multi-target unattended imaging
              http://ccdcommander.astromatt.com/

              Saturday, June 30, 2007, 5:49:01 PM, actx03 wrote:

              > Hello to Everyone, I just posted my first attempt at imaging in
              > narrowband using the Hubble Map format in the Dr. Jim P folder. M27
              > is low in the East and the city light dome so it seemed a good time to
              > try it. My question is about the SII channel. I do not yet have an
              > SII filter, although hopes are high for my upcoming birthday. I opted
              > to use 80 minutes of RED taken in 10 minute subs last week as a
              > substitute. I also got only two 20 minute Ha shots before clouds
              > ended the night. The OIII line was 100 minutes at 20 minutes each.
              > Should I try some other combination that will look better? I will add
              > to the Ha line tonight if things hold. I know some have used only Ha
              > and OIII. Also, can anyone suggest other targets for this type of
              > imaging that are north of about -20 degrees South. The area around
              > Cygnus seems promising, but limited to mainly red colored objects.
              > Any help is appreciated and comments on processing are also welcomed.
              > Drs. Jim and Linda Powell
              > SV-102 APO doublet
              > SV-102DN
              > Nighthawk
              > SV-145 ON ORDER!





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