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reducer/fattener for mewlon 250

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  • weileong27
    Hi, Finally getting my mewlon 250 soon, in about a month s time but sadly that will be in 2003 :) in preparation for Mars in August. I ll like to know if
    Message 1 of 8 , Dec 1, 2002
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      Hi,

      Finally getting my mewlon 250 soon, in about a month's time but sadly
      that will be in 2003 :) in preparation for Mars in August.

      I'll like to know if anyone had use the reducer/flattener for the
      mewlon 250 before?

      Is this really necessary? say for high power lunar imaging?
      I gather this will reduce the focal ratio down to f/9.

      Is there a separate f/12 flattener avaliable?

      Thanks for reading.
    • weileong27
      ... Gene, Thanks for the quick reply. What I meant for example if I just want to do some imaging at prime focus, will the reducer be necessary, ie to correct
      Message 2 of 8 , Dec 2, 2002
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        --- In UncensoredTakGroup@y..., Gene Horr <genehorr@t...> wrote:

        > > Is this really necessary? say for high power lunar imaging?
        >
        > No. Use a high end barlow like the Tak Vari-Extender or the
        > Televue Big Barlow.

        Gene,

        Thanks for the quick reply.
        What I meant for example if I just want to do some imaging at prime
        focus, will the reducer be necessary, ie to correct for off-axis
        abberation. How bad is that on the mewlon?

        An example would be lunar imaging where you want to use the full
        field avaliable.

        For planetary work, the off axis abberation can be ignored since we
        only use the center part of the FOV.
      • AA Johnah Fish Estates
        There is a reducer and corrector available for the Mewlon 210, 150, 300 ( not sure about the 180 though). They are not necessary for high power Lunar or Planet
        Message 3 of 8 , Dec 2, 2002
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          There is a reducer and corrector available for the Mewlon 210, 150, 300 (
          not sure about the 180 though).
          They are not necessary for high power Lunar or Planet observing. I like the
          Tak Vari-extender or the AP Bacron Barlow. Both work very well with the
          Mewlon. I would think that any other Barlow would work well for this scope
          too.

          Mark



          ----- Original Message -----
          From: "Gene Horr" <genehorr@...>
          To: <UncensoredTakGroup@yahoogroups.com>
          Sent: Monday, December 02, 2002 8:10 PM
          Subject: Re: [UncensoredTakGroup] reducer/fattener for mewlon 250


          > weileong27 wrote:
          >
          > > Finally getting my mewlon 250 soon, in about a month's time but sadly
          > > that will be in 2003 :) in preparation for Mars in August.
          > >
          > > I'll like to know if anyone had use the reducer/flattener for the
          > > mewlon 250 before?
          >
          > Works great.
          >
          > > Is this really necessary? say for high power lunar imaging?
          >
          > No. Use a high end barlow like the Tak Vari-Extender or the
          > Televue Big Barlow.
          >
          > > Is there a separate f/12 flattener avaliable?
          >
          > Not sure.
          >
          > Gene Horr
          > genehorr@...
          >
        • Gene Horr
          ... Ah. Sorry for the misunderstanding. I m not sure. Are you planning CCD or film work? Gene Horr genehorr@texas.net
          Message 4 of 8 , Dec 2, 2002
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            weileong27 wrote:

            > Thanks for the quick reply.
            > What I meant for example if I just want to do some imaging at prime
            > focus, will the reducer be necessary, ie to correct for off-axis
            > abberation. How bad is that on the mewlon?
            >
            > An example would be lunar imaging where you want to use the full
            > field avaliable.

            Ah. Sorry for the misunderstanding. I'm not sure. Are you planning
            CCD or film work?

            Gene Horr
            genehorr@...
          • weileong27
            ... planning CCD or film work? No problem :) Planning some shots with digital cameras. I ll just get the reducer in case.
            Message 5 of 8 , Dec 2, 2002
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              --- In UncensoredTakGroup@y..., Gene Horr <genehorr@t...> wrote:

              > Ah. Sorry for the misunderstanding. I'm not sure. Are you
              planning CCD or film work?

              No problem :) Planning some shots with digital cameras. I'll just get
              the reducer in case.
            • Gene Horr
              ... Well, I won t argue with this as I think that you ll use it for deep sky work anyway. But for CCD I would highly doubt that it would be necessary. The
              Message 6 of 8 , Dec 2, 2002
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                weileong27 wrote:

                > > Ah. Sorry for the misunderstanding. I'm not sure. Are you
                > planning CCD or film work?
                >
                > No problem :) Planning some shots with digital cameras. I'll just get
                > the reducer in case.

                Well, I won't argue with this as I think that you'll use it for deep
                sky work anyway. But for CCD I would highly doubt that it would be
                necessary. The curvature radius will be so long and the focal
                "plane" so thick that across the area of a chip should all be in focus.

                Gene Horr
                genehorr@...
              • Gene Horr
                ... Works great. ... No. Use a high end barlow like the Tak Vari-Extender or the Televue Big Barlow. ... Not sure. Gene Horr genehorr@texas.net
                Message 7 of 8 , Dec 2, 2002
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                  weileong27 wrote:

                  > Finally getting my mewlon 250 soon, in about a month's time but sadly
                  > that will be in 2003 :) in preparation for Mars in August.
                  >
                  > I'll like to know if anyone had use the reducer/flattener for the
                  > mewlon 250 before?

                  Works great.

                  > Is this really necessary? say for high power lunar imaging?

                  No. Use a high end barlow like the Tak Vari-Extender or the
                  Televue Big Barlow.

                  > Is there a separate f/12 flattener avaliable?

                  Not sure.

                  Gene Horr
                  genehorr@...
                • Chris Johnston
                  I fully agree with Gene. Get the R/F for the lower F/L but it is not necessary to correct curvature of field. Chris ... get ... focus.
                  Message 8 of 8 , Dec 2, 2002
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                    I fully agree with Gene. Get the R/F for the lower F/L but it is not
                    necessary to correct curvature of field.

                    Chris

                    --- In UncensoredTakGroup@y..., Gene Horr <genehorr@t...> wrote:
                    > weileong27 wrote:
                    >
                    > > > Ah. Sorry for the misunderstanding. I'm not sure. Are you
                    > > planning CCD or film work?
                    > >
                    > > No problem :) Planning some shots with digital cameras. I'll just
                    get
                    > > the reducer in case.
                    >
                    > Well, I won't argue with this as I think that you'll use it for deep
                    > sky work anyway. But for CCD I would highly doubt that it would be
                    > necessary. The curvature radius will be so long and the focal
                    > "plane" so thick that across the area of a chip should all be in
                    focus.
                    >
                    > Gene Horr
                    > genehorr@t...
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