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Re: TMB 100/800 CNC Classic

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  • izar21093
    Wayne, I conversed with Tom and Marcus several times about the 100/800 Classic after purchase. I still have not seen anything better at star parties. Usually,
    Message 1 of 11 , May 31, 2008
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      Wayne,

      I conversed with Tom and Marcus several times about the 100/800
      Classic after purchase. I still have not seen anything better at star
      parties. Usually, the "better" view is through a significantly larger
      aperture, and not always then.

      The addition of the Feather Touch focuser has increased the pleasure
      value by giving me the original focuser, the "coarse" FT focus and
      the "fine" FT focus for high magnification work.

      I hope others have not sidelined these scopes.

      Bill G




      --- In tmboptical@yahoogroups.com, Wayne G <fomalhaut@...> wrote:
      >
      > izar21093 wrote:
      > > Other than myself, is any one still using the 4" f-8 scoope on a
      > > regular basis? Mine has become my main visual scope and always
      delivers
      > > an excellent performance.
      > >
      >
      > WG: Bill, I would certainly hope so, as the 4" Apo is perhaps the
      most
      > common, popular and favored sizes of all Apos out there and the
      100/800
      > CNC was touted by Tom himself (who kept one in his personal
      collection
      > with a strehl around .99 I believe) as perhaps the very pinnacle of
      all
      > the lenses he ever designed through LZOS.
      >
      > If I ever buy another APM/TMB it would most likely be this one, in
      the
      > classic CNC tube of course--- perhaps the best 4" apochromat ever
      made IMO.
      >
      > WayneG
      >
    • david albritton
      Hi Wayne, I remember reading an article by Thomas Back. He stated that his personal 100/800 had a strehl of .997 (which is supposedly the highest strehl LZOS
      Message 2 of 11 , Jun 1, 2008
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        Hi Wayne,
        I remember reading an article by Thomas Back. He stated that his personal 100/800 had a strehl of .997 (which is supposedly the highest strehl LZOS lense). He also stated that his Astro-physics 180mm f/9 EDT had a strehl of .9975. Roland Christen gave him a copy of the report. That's probably as perfect as your gonna get. I was surprised to find the strehl report for my 100/800 lightweight shows a .993. I don't know much about what the numbers mean other than this would be a highly corrected lense. Can't wait to view through it.

        Wayne G <fomalhaut@...> wrote:
        izar21093 wrote:
        > Other than myself, is any one still using the 4" f-8 scoope on a
        > regular basis? Mine has become my main visual scope and always delivers
        > an excellent performance.
        >

        WG: Bill, I would certainly hope so, as the 4" Apo is perhaps the most
        common, popular and favored sizes of all Apos out there and the 100/800
        CNC was touted by Tom himself (who kept one in his personal collection
        with a strehl around .99 I believe) as perhaps the very pinnacle of all
        the lenses he ever designed through LZOS.

        If I ever buy another APM/TMB it would most likely be this one, in the
        classic CNC tube of course--- perhaps the best 4" apochromat ever made IMO.

        WayneG







        [Non-text portions of this message have been removed]
      • david albritton
        Hi Bill, Thanks for the info. My plans are to use this scope as a kinda grab and go scope w/ a quick set-up time. I was planning on purchasing a non-goto G-8
        Message 3 of 11 , Jun 1, 2008
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          Hi Bill,
          Thanks for the info. My plans are to use this scope as a kinda grab and go scope w/ a quick set-up time. I was planning on purchasing a non-goto G-8 and use a Kendrick power pack. This is all very new to me. I'll be green for some time but I have researched a lot of products on the market and have read a lot of reviews. I am still learning a lot. I'm not at all familiar with the Argo Navis or Sky Commander programs or even how to go about using one, for that matter. I know nothing about digital setting circles, either. I would appreciate any advice and recommendations on setting this scope up. You might have to explain some things in laymens terms until I understand some of the lingo.
          Thanks, David

          izar21093 <izar21093@...> wrote:
          I'm sure you will not be disappointed. I have not used one of the
          LW's but I believe the optics are the same as mine. I have pushed it
          to 400x under very good skies and believe it could go beyond 400x
          with better skies.

          Most of my use is visual but I have done a bit of double-star
          measurement to compare with measurements made with my six inch
          reflector years ago.

          These scopes are a joy to use. With the G-8 I highly recommend the
          Argo Navis for pointing. The AN complements the TMB quality extremely
          well. The combination of great mount, scope and computer make every
          night out pleasureable.

          Bill G

          --- In tmboptical@yahoogroups.com, david albritton <mator5872@...>
          wrote:
          >
          > Hi Bill,
          > I have a lightweight 4" f-8 but have yet had a chance to view
          through it. I am very pleased with the quality of the OTA. The
          FeatherTouch focuser is awesome. I am currently saving to get a
          Losmandy G-8. This is my first scope purchase so I am pretty excited.
          Can't wait to view through it.
          >
          > izar21093 <izar21093@...> wrote:
          > Other than myself, is any one still using the 4" f-8
          scoope on a
          > regular basis? Mine has become my main visual scope and always
          delivers
          > an excellent performance.
          >
          > It is mounted on a well maintained CI-700 GEM with an Argo Navis
          for
          > pointing under my bright urban sky. The FeatherTouch focuser is
          superb.
          >
          > The scope (AKA: "Fancy Pants") is still as pictured in the photo
          > section.
          >
          > Bill G
          >
          >
          >
          >
          >
          >
          >
          > [Non-text portions of this message have been removed]
          >







          [Non-text portions of this message have been removed]
        • Wayne G
          ... WG: As do I, Bill, as I believe more so than any other product he ever made or designed since, the real heart and soul of Thomas lives on in these
          Message 4 of 11 , Jun 1, 2008
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            izar21093 wrote:
            > Wayne,
            >
            > <snip> I hope others have not sidelined these scopes.
            >
            > Bill G
            >

            WG: As do I, Bill, as I believe more so than any other product he ever
            made or designed since, the real heart and soul of Thomas lives on in
            these original design refractors--- these were what Thomas envisioned
            he wanted in a telescope, these were his dream--- what he put forth to
            the world to exclaim: "Here I Am!"; this is what he came up with
            starting from a clean slate where anything was possible and all options
            were on the table to achieve his 'ultimate' apochromat.

            WayneG
          • Wayne G
            ... WG: A theoretically perfect lens would have a strehl ratio of 1.0. In practice though, anything at or above .95 is sensibly perfect and considered a
            Message 5 of 11 , Jun 1, 2008
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              david albritton wrote:
              > I don't know much about what the numbers mean other than this would be a highly corrected lense. Can't wait to view through it.
              >

              WG: A theoretically perfect lens would have a strehl ratio of 1.0. In
              practice though, anything at or above .95 is sensibly "perfect" and
              considered a 'planetary telescope.' The strehl number (easier for
              people to relate to than rms) is derived from the r.m.s. value and
              relates to how well the optic focuses all light from a point source to
              be kept within the diffraction disc.

              A perfect lens would focus 100% of all light within the diffraction
              disc. A scope of .98 strehl focuses 98% of all available light to where
              it should go.

              But when you get to numbers as high as some you mentioned, I begin to
              wonder about how the tests were done--- I do not believe any test is
              sensitive enough to accurately determine a strehl of .9975, and it
              really doesn't make any difference in use over the images given by a
              scope of .9875--- in focus, you won't see any difference at all and
              only the truly gifted star tester has a chance of seeing the difference
              out of focus (where no scope operates anyway).

              Once you get beyond .95, you are "there" and all lenses made by LZOS are
              guaranteed to be this good or better.

              WayneG
            • izar21093
              Sounds good David. Don t bother with digital setting circles until you need them or feel ready for them. Learn the sky first and have fun. I taught my kids to
              Message 6 of 11 , Jun 1, 2008
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                Sounds good David.

                Don't bother with digital setting circles until you need them or feel
                ready for them. Learn the sky first and have fun. I taught my kids to
                drive a standard shift before letting them use an automatic.

                I use a jump start battery to power the mount when away from home. At
                home I use a 12v power supply. Very basic.

                Enjoy.

                Bill G


                --- In tmboptical@yahoogroups.com, david albritton <mator5872@...>
                wrote:
                >
                > Hi Bill,
                > Thanks for the info. My plans are to use this scope as a kinda
                grab and go scope w/ a quick set-up time. I was planning on
                purchasing a non-goto G-8 and use a Kendrick power pack. This is all
                very new to me. I'll be green for some time but I have researched a
                lot of products on the market and have read a lot of reviews. I am
                still learning a lot. I'm not at all familiar with the Argo Navis or
                Sky Commander programs or even how to go about using one, for that
                matter. I know nothing about digital setting circles, either. I
                would appreciate any advice and recommendations on setting this scope
                up. You might have to explain some things in laymens terms until I
                understand some of the lingo.
                > Thanks, David
                >
                > izar21093 <izar21093@...> wrote:
                > I'm sure you will not be disappointed. I have not used
                one of the
                > LW's but I believe the optics are the same as mine. I have pushed
                it
                > to 400x under very good skies and believe it could go beyond 400x
                > with better skies.
                >
                > Most of my use is visual but I have done a bit of double-star
                > measurement to compare with measurements made with my six inch
                > reflector years ago.
                >
                > These scopes are a joy to use. With the G-8 I highly recommend the
                > Argo Navis for pointing. The AN complements the TMB quality
                extremely
                > well. The combination of great mount, scope and computer make every
                > night out pleasureable.
                >
                > Bill G
                >
                > --- In tmboptical@yahoogroups.com, david albritton <mator5872@>
                > wrote:
                > >
                > > Hi Bill,
                > > I have a lightweight 4" f-8 but have yet had a chance to view
                > through it. I am very pleased with the quality of the OTA. The
                > FeatherTouch focuser is awesome. I am currently saving to get a
                > Losmandy G-8. This is my first scope purchase so I am pretty
                excited.
                > Can't wait to view through it.
                > >
                > > izar21093 <izar21093@> wrote:
                > > Other than myself, is any one still using the 4" f-8
                > scoope on a
                > > regular basis? Mine has become my main visual scope and always
                > delivers
                > > an excellent performance.
                > >
                > > It is mounted on a well maintained CI-700 GEM with an Argo Navis
                > for
                > > pointing under my bright urban sky. The FeatherTouch focuser is
                > superb.
                > >
                > > The scope (AKA: "Fancy Pants") is still as pictured in the photo
                > > section.
                > >
                > > Bill G
                > >
                > >
                > >
                > >
                > >
                > >
                > >
                > > [Non-text portions of this message have been removed]
                > >
                >
                >
                >
                >
                >
                >
                >
                > [Non-text portions of this message have been removed]
                >
              • izar21093
                Roger that !! ... ever ... in ... envisioned ... forth to ... options
                Message 7 of 11 , Jun 1, 2008
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                  Roger that !!



                  --- In tmboptical@yahoogroups.com, Wayne G <fomalhaut@...> wrote:
                  >
                  > izar21093 wrote:
                  > > Wayne,
                  > >
                  > > <snip> I hope others have not sidelined these scopes.
                  > >
                  > > Bill G
                  > >
                  >
                  > WG: As do I, Bill, as I believe more so than any other product he
                  ever
                  > made or designed since, the real heart and soul of Thomas lives on
                  in
                  > these original design refractors--- these were what Thomas
                  envisioned
                  > he wanted in a telescope, these were his dream--- what he put
                  forth to
                  > the world to exclaim: "Here I Am!"; this is what he came up with
                  > starting from a clean slate where anything was possible and all
                  options
                  > were on the table to achieve his 'ultimate' apochromat.
                  >
                  > WayneG
                  >
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