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Is Megrez 72FD an APO?

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  • mirfak30
    I can not say yes . Last night, just 11 hours ago in Korea, I was in a mountain together with 9 club members.(Our club name is Seoul Astronomy Club. Seoul
    Message 1 of 20 , Mar 14, 2008
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      I can "not" say "yes".

      Last night, just 11 hours ago in Korea, I was in a mountain together
      with 9 club members.(Our club name is Seoul Astronomy Club. Seoul is
      the capital city of Korea) Under the sky of 7~8/10 seeing there were
      12 scopes; Takahashi, Pentax, Vixen, Celestron, Skywatcher... so on.
      Among them really pretty Megrez 72FD with Takahashi FS60C as a guide
      scope.

      It was ready to be tested for visual performance after a few shots
      of imaging. We looked Arcturus through Vixen LV 2.5mm(x173) and saw
      something not expected; fresnel rings full of CA! Even in-focus-
      image looked so much colorful. To make it worse about 1/7 of airy
      disk was fuzzy similar to a tail of a comet. We moved the scope to
      Saturn. And?, same; colorful Saturn. We thought the eyepiece might
      have big problems so we changed it to Takahashi Hi-Le 3.6mm(x120)
      then Pentax XW 7mm and 5mm on 2.5x Powermate (x154 and x216) but all
      the same; colorful and fuzzy.

      Conclusion? FD72 has the problems.

      Unfortunately for the 72FD we had Takahashi FS-60 and FS-78. So the
      72FD gave us bad feeling; a seriously defective optics.

      Now what shall we do?

      Suk
    • zverjuga2005
      Hi Suk. I did not have a chance to look through M72, but I have ZS66. And ZS66 is a great scope for the price I paid for it (around EUR240). Maybe if I will
      Message 2 of 20 , Mar 16, 2008
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        Hi Suk.
        I did not have a chance to look through M72, but I have ZS66.
        And ZS66 is a great scope for the price I paid for it (around EUR240).
        Maybe if I will compare it with Takahashi FS60C it will be not so
        great, but I know that Tak scope will cost me double or triple what
        WO telescopes cost.
        For example, in Europe M72 costs EUR389 ($580) for OTA.
        Takahashi FS60C will be around EUR640 ($960).

        I am happy with ZS66 and for $960 I can buy M90 or M110.

        If you want the best telescope then Tak, AP, TEC will be the right
        one. But if you want to safe some money then you should go for WO.

        Another thought: I don't think doublet can be a true APO.

        Few times I used friend's M110 which is doublet too. It has some
        color with high power eyepiece. Color correction of M110 is better
        then Achromat, but it's not a true APO.
        FLT110 is APO, but it costs two times more then M110.

        That's why we always have to think about the price we paid for it.

        Tomas.

        --- In William-Optics@yahoogroups.com, "mirfak30" <mirfak30@...>
        wrote:
        >
        > I can "not" say "yes".
        >
        > Last night, just 11 hours ago in Korea, I was in a mountain
        together
        > with 9 club members.(Our club name is Seoul Astronomy Club. Seoul
        is
        > the capital city of Korea) Under the sky of 7~8/10 seeing there
        were
        > 12 scopes; Takahashi, Pentax, Vixen, Celestron, Skywatcher... so
        on.
        > Among them really pretty Megrez 72FD with Takahashi FS60C as a
        guide
        > scope.
        >
        > It was ready to be tested for visual performance after a few shots
        > of imaging. We looked Arcturus through Vixen LV 2.5mm(x173) and saw
        > something not expected; fresnel rings full of CA! Even in-focus-
        > image looked so much colorful. To make it worse about 1/7 of airy
        > disk was fuzzy similar to a tail of a comet. We moved the scope to
        > Saturn. And?, same; colorful Saturn. We thought the eyepiece might
        > have big problems so we changed it to Takahashi Hi-Le 3.6mm(x120)
        > then Pentax XW 7mm and 5mm on 2.5x Powermate (x154 and x216) but
        all
        > the same; colorful and fuzzy.
        >
        > Conclusion? FD72 has the problems.
        >
        > Unfortunately for the 72FD we had Takahashi FS-60 and FS-78. So the
        > 72FD gave us bad feeling; a seriously defective optics.
        >
        > Now what shall we do?
        >
        > Suk
        >
      • ajax672000
        Hello Suk. I am relatively new to this hobby and have only recently acquired my scopes with little chance to test them due to the dreadful weather we ve been
        Message 3 of 20 , Mar 17, 2008
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          Hello Suk. I am relatively new to this hobby and have only recently
          acquired my scopes with little chance to test them due to the
          dreadful weather we've been getting here in the U.K. I tried my
          Megrez 72FD during a daytime high contrast test using the far away
          branches of a bare tree set against the bright sky and noticed
          colour fringing of purples greens and yellows with a 3mm eyepiece
          yielding 144x magnification. However, when I did manage to do some
          nighttime observing I was pleasantly surprised! I had a very good
          view of Saturn and the Moon showed no colour that I can detect. I
          invited my family to the eyepiece and there was just a lot of
          ohhing! and ahhing! and this coming from people with no interest in
          astronomy and little in the way of expectation, just pure
          unadulterated appreciation. Anyway, I had better get to the point; I
          thought it strange that I can detect colour during the day yet none
          on the Moon; after a little deliberation I decided that it might be
          a cool down issue, so I mounted the scope up indoors (did not have
          time to wait for a cooldown outside) and set about testing thorugh
          an open door on the same subject with the same eyepiece only this
          time yielding virtually colour free views. I repeat I am still very
          new to this hobby with only my very limited experiences to offer. I
          am very pleased with my 72FD thus far! but I will keep you updated
          as I live and learn.

          Regards

          Jack.

          B.t.w. if you are looking through an open door or window please be
          aware of air currents.

          --- In William-Optics@yahoogroups.com, "mirfak30" <mirfak30@...>
          wrote:
          >
          > I can "not" say "yes".
          >
          > Last night, just 11 hours ago in Korea, I was in a mountain
          together
          > with 9 club members.(Our club name is Seoul Astronomy Club. Seoul
          is
          > the capital city of Korea) Under the sky of 7~8/10 seeing there
          were
          > 12 scopes; Takahashi, Pentax, Vixen, Celestron, Skywatcher... so
          on.
          > Among them really pretty Megrez 72FD with Takahashi FS60C as a
          guide
          > scope.
          >
          > It was ready to be tested for visual performance after a few shots
          > of imaging. We looked Arcturus through Vixen LV 2.5mm(x173) and
          saw
          > something not expected; fresnel rings full of CA! Even in-focus-
          > image looked so much colorful. To make it worse about 1/7 of airy
          > disk was fuzzy similar to a tail of a comet. We moved the scope to
          > Saturn. And?, same; colorful Saturn. We thought the eyepiece might
          > have big problems so we changed it to Takahashi Hi-Le 3.6mm(x120)
          > then Pentax XW 7mm and 5mm on 2.5x Powermate (x154 and x216) but
          all
          > the same; colorful and fuzzy.
          >
          > Conclusion? FD72 has the problems.
          >
          > Unfortunately for the 72FD we had Takahashi FS-60 and FS-78. So
          the
          > 72FD gave us bad feeling; a seriously defective optics.
          >
          > Now what shall we do?
          >
          > Suk
          >
        • Paul Gordon
          The BBC Sky at Night magazine has a good review about the Megrez 72FD It would be considered an APO as it uses ED glass (It s an ED Doublet) Regards, -- Paul
          Message 4 of 20 , Mar 17, 2008
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            The BBC Sky at Night magazine has a good review about the Megrez 72FD
            It would be considered an APO as it uses ED glass (It's an ED Doublet)

            Regards,

            --
            Paul Gordon
            paul@...
            http://www.madpc.co.uk

            -----Original Message-----
            From: William-Optics@yahoogroups.com [mailto:William-Optics@yahoogroups.com]
            On Behalf Of ajax672000
            Sent: 2008-03-17 15:50
            To: William-Optics@yahoogroups.com
            Subject: [William Optics] Re: Is Megrez 72FD an APO?

            Hello Suk. I am relatively new to this hobby and have only recently
            acquired my scopes with little chance to test them due to the
            dreadful weather we've been getting here in the U.K. I tried my
            Megrez 72FD during a daytime high contrast test using the far away
            branches of a bare tree set against the bright sky and noticed
            colour fringing of purples greens and yellows with a 3mm eyepiece
            yielding 144x magnification. However, when I did manage to do some
            nighttime observing I was pleasantly surprised! I had a very good
            view of Saturn and the Moon showed no colour that I can detect. I
            invited my family to the eyepiece and there was just a lot of
            ohhing! and ahhing! and this coming from people with no interest in
            astronomy and little in the way of expectation, just pure
            unadulterated appreciation. Anyway, I had better get to the point; I
            thought it strange that I can detect colour during the day yet none
            on the Moon; after a little deliberation I decided that it might be
            a cool down issue, so I mounted the scope up indoors (did not have
            time to wait for a cooldown outside) and set about testing thorugh
            an open door on the same subject with the same eyepiece only this
            time yielding virtually colour free views. I repeat I am still very
            new to this hobby with only my very limited experiences to offer. I
            am very pleased with my 72FD thus far! but I will keep you updated
            as I live and learn.

            Regards

            Jack.

            B.t.w. if you are looking through an open door or window please be
            aware of air currents.

            --- In William-Optics@yahoogroups.com, "mirfak30" <mirfak30@...>
            wrote:
            >
            > I can "not" say "yes".
            >
            > Last night, just 11 hours ago in Korea, I was in a mountain
            together
            > with 9 club members.(Our club name is Seoul Astronomy Club. Seoul
            is
            > the capital city of Korea) Under the sky of 7~8/10 seeing there
            were
            > 12 scopes; Takahashi, Pentax, Vixen, Celestron, Skywatcher... so
            on.
            > Among them really pretty Megrez 72FD with Takahashi FS60C as a
            guide
            > scope.
            >
            > It was ready to be tested for visual performance after a few shots
            > of imaging. We looked Arcturus through Vixen LV 2.5mm(x173) and
            saw
            > something not expected; fresnel rings full of CA! Even in-focus-
            > image looked so much colorful. To make it worse about 1/7 of airy
            > disk was fuzzy similar to a tail of a comet. We moved the scope to
            > Saturn. And?, same; colorful Saturn. We thought the eyepiece might
            > have big problems so we changed it to Takahashi Hi-Le 3.6mm(x120)
            > then Pentax XW 7mm and 5mm on 2.5x Powermate (x154 and x216) but
            all
            > the same; colorful and fuzzy.
            >
            > Conclusion? FD72 has the problems.
            >
            > Unfortunately for the 72FD we had Takahashi FS-60 and FS-78. So
            the
            > 72FD gave us bad feeling; a seriously defective optics.
            >
            > Now what shall we do?
            >
            > Suk
            >



            ------------------------------------

            www.williamoptics.com www.williamopticsracing.comYahoo!
            Groups Links
          • Christoph Bosshard
            Hello Suk Here is the link to a German test of the Megrez 72: http://www.astro-foren.de/showthread.php?t=9190 Looking at the results for colour you can see
            Message 5 of 20 , Mar 17, 2008
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              Hello Suk


              Here is the link to a German test of the Megrez 72:
              http://www.astro-foren.de/showthread.php?t=9190

              Looking at the results for colour you can see that it is not that well
              corrected. When using an Amici Prisma the results are improved. With
              the prisma it reaches the level of a semi Apo.

              Cheers
              Chris
            • Dan
              Hi Tomas, You made a great point in that an TRUE APO comes at a premium price. I do not believe any company can produce true APO quality lense systems at the
              Message 6 of 20 , Mar 17, 2008
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                Hi Tomas,
                You made a great point in that an TRUE APO comes at a premium
                price. I do not believe any company can produce true APO quality lense
                systems at the prices that some scopes are being sold for.
                But this brings about another discussion in what defines an APO
                scope. Are there any true universally accepted measurements that
                define it or is it left up to a company's marketing department.If it
                is left up to marketing in which case Cavet Emptor (buyer beware) is
                the prevailing statement.
                Dan



                --- In William-Optics@yahoogroups.com, "zverjuga2005"
                <zverjuga2005@...> wrote:
                >
                > Hi Suk.
                > I did not have a chance to look through M72, but I have ZS66.
                > And ZS66 is a great scope for the price I paid for it (around EUR240).
                > Maybe if I will compare it with Takahashi FS60C it will be not so
                > great, but I know that Tak scope will cost me double or triple what
                > WO telescopes cost.
                > For example, in Europe M72 costs EUR389 ($580) for OTA.
                > Takahashi FS60C will be around EUR640 ($960).
                >
                > I am happy with ZS66 and for $960 I can buy M90 or M110.
                >
                > If you want the best telescope then Tak, AP, TEC will be the right
                > one. But if you want to safe some money then you should go for WO.
                >
                > Another thought: I don't think doublet can be a true APO.
                >
                > Few times I used friend's M110 which is doublet too. It has some
                > color with high power eyepiece. Color correction of M110 is better
                > then Achromat, but it's not a true APO.
                > FLT110 is APO, but it costs two times more then M110.
                >
                > That's why we always have to think about the price we paid for it.
                >
                > Tomas.
                >
                > --- In William-Optics@yahoogroups.com, "mirfak30" <mirfak30@>
                > wrote:
                > >
                > > I can "not" say "yes".
                > >
                > > Last night, just 11 hours ago in Korea, I was in a mountain
                > together
                > > with 9 club members.(Our club name is Seoul Astronomy Club. Seoul
                > is
                > > the capital city of Korea) Under the sky of 7~8/10 seeing there
                > were
                > > 12 scopes; Takahashi, Pentax, Vixen, Celestron, Skywatcher... so
                > on.
                > > Among them really pretty Megrez 72FD with Takahashi FS60C as a
                > guide
                > > scope.
                > >
                > > It was ready to be tested for visual performance after a few shots
                > > of imaging. We looked Arcturus through Vixen LV 2.5mm(x173) and saw
                > > something not expected; fresnel rings full of CA! Even in-focus-
                > > image looked so much colorful. To make it worse about 1/7 of airy
                > > disk was fuzzy similar to a tail of a comet. We moved the scope to
                > > Saturn. And?, same; colorful Saturn. We thought the eyepiece might
                > > have big problems so we changed it to Takahashi Hi-Le 3.6mm(x120)
                > > then Pentax XW 7mm and 5mm on 2.5x Powermate (x154 and x216) but
                > all
                > > the same; colorful and fuzzy.
                > >
                > > Conclusion? FD72 has the problems.
                > >
                > > Unfortunately for the 72FD we had Takahashi FS-60 and FS-78. So the
                > > 72FD gave us bad feeling; a seriously defective optics.
                > >
                > > Now what shall we do?
                > >
                > > Suk
                > >
                >
              • rhofm
                Abbe s definition of apochromatism was the following: an objective corrected parfocally for three widely spaced wavelengths and corrected for spherical
                Message 7 of 20 , Mar 17, 2008
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                  Abbe's definition of apochromatism was the following: an objective corrected parfocally for
                  three widely spaced wavelengths and corrected for spherical aberration and coma for two
                  widely separated wavelengths. Sometimes only the first part of the definition is used to
                  describe an apochromat.

                  For such a small objective a triplet is not necessary. For a 110mm this is different, although
                  there are good apos with only a doublet.

                  Is the 72 an apo? I haven't seen a spot diagram for the 72, so I don't know if it was intended
                  as one. I have used mine only for a short time and was very pleased with the views, but I've
                  never used very high magnifications. I bought the telescope as a carry-everywhere widefield
                  scope for visual and photographic applications and as a guidescope. I was impressed by the
                  photographic performance for such a relatively cheap and small scope.

                  Looking at the forum posts I can see that some were lucky and got a good one, some
                  weren't.

                  -Rainer
                • Paul Gordon
                  Hi Guy s, Well I picked my Megrez 72 up after the Astrofeast show in London. I got it at the Bargain price of £260 new!! (Special offer at the show) And have
                  Message 8 of 20 , Mar 18, 2008
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                    Hi Guy's,

                    Well I picked my Megrez 72 up after the Astrofeast show in London.
                    I got it at the Bargain price of £260 new!! (Special offer at the show)
                    And have to say the build quality is superb.
                    It is very nearly the Cheapest 'near' APO you can buy with a build quality
                    better than most of its rivals.
                    (The colour correction of mine seems to be very good).
                    I also own a Vixen 103s which is also a very good scope but not built as
                    solid as the WO range.

                    The Sky at Night review gave it an overall score of 95% and the review was
                    done by Peter Lawrence.
                    In and out of focus colour correction appears to be good.
                    Using a DSLR you will get elongation of the Stars near the edges unless you
                    use a field flattener.
                    One comment made was they needed to put a tube extender on the M72 as it
                    would not quite make focus (I assume with the DSLR) not uncommon with
                    Refractors.

                    I had a ZS66 SD 2 thing's made me upgrade to the Megrez 72
                    1/ 2" focuser
                    2/ the same focuser used in the Excellent Megrez 90
                    More solid and positive than the ZS66 SD.

                    HTH,

                    --
                    Paul Gordon
                    paul@...
                    http://www.madpc.co.uk

                    -----Original Message-----
                    From: William-Optics@yahoogroups.com [mailto:William-Optics@yahoogroups.com]
                    On Behalf Of zverjuga2005
                    Sent: 2008-03-17 04:00
                    To: William-Optics@yahoogroups.com
                    Subject: [William Optics] Re: Is Megrez 72FD an APO?

                    Hi Suk.
                    I did not have a chance to look through M72, but I have ZS66.
                    And ZS66 is a great scope for the price I paid for it (around EUR240).
                    Maybe if I will compare it with Takahashi FS60C it will be not so
                    great, but I know that Tak scope will cost me double or triple what
                    WO telescopes cost.
                    For example, in Europe M72 costs EUR389 ($580) for OTA.
                    Takahashi FS60C will be around EUR640 ($960).

                    I am happy with ZS66 and for $960 I can buy M90 or M110.

                    If you want the best telescope then Tak, AP, TEC will be the right
                    one. But if you want to safe some money then you should go for WO.

                    Another thought: I don't think doublet can be a true APO.

                    Few times I used friend's M110 which is doublet too. It has some
                    color with high power eyepiece. Color correction of M110 is better
                    then Achromat, but it's not a true APO.
                    FLT110 is APO, but it costs two times more then M110.

                    That's why we always have to think about the price we paid for it.

                    Tomas.

                    --- In William-Optics@yahoogroups.com, "mirfak30" <mirfak30@...>
                    wrote:
                    >
                    > I can "not" say "yes".
                    >
                    > Last night, just 11 hours ago in Korea, I was in a mountain
                    together
                    > with 9 club members.(Our club name is Seoul Astronomy Club. Seoul
                    is
                    > the capital city of Korea) Under the sky of 7~8/10 seeing there
                    were
                    > 12 scopes; Takahashi, Pentax, Vixen, Celestron, Skywatcher... so
                    on.
                    > Among them really pretty Megrez 72FD with Takahashi FS60C as a
                    guide
                    > scope.
                    >
                    > It was ready to be tested for visual performance after a few shots
                    > of imaging. We looked Arcturus through Vixen LV 2.5mm(x173) and saw
                    > something not expected; fresnel rings full of CA! Even in-focus-
                    > image looked so much colorful. To make it worse about 1/7 of airy
                    > disk was fuzzy similar to a tail of a comet. We moved the scope to
                    > Saturn. And?, same; colorful Saturn. We thought the eyepiece might
                    > have big problems so we changed it to Takahashi Hi-Le 3.6mm(x120)
                    > then Pentax XW 7mm and 5mm on 2.5x Powermate (x154 and x216) but
                    all
                    > the same; colorful and fuzzy.
                    >
                    > Conclusion? FD72 has the problems.
                    >
                    > Unfortunately for the 72FD we had Takahashi FS-60 and FS-78. So the
                    > 72FD gave us bad feeling; a seriously defective optics.
                    >
                    > Now what shall we do?
                    >
                    > Suk
                    >



                    ------------------------------------

                    www.williamoptics.com www.williamopticsracing.comYahoo!
                    Groups Links
                  • zverjuga2005
                    Paul, after your comments i want to upgrade my ZS66 :-) It seems either your scope is better then Suk s M72 or his expectations are too high as he compared it
                    Message 9 of 20 , Mar 18, 2008
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                      Paul,
                      after your comments i want to upgrade my ZS66 :-)

                      It seems either your scope is better then Suk's M72 or his
                      expectations are too high as he compared it to Tak.

                      Tomas.
                      --- In William-Optics@yahoogroups.com, "Paul Gordon" <paul@...> wrote:
                      >
                      > Hi Guy's,
                      >
                      > Well I picked my Megrez 72 up after the Astrofeast show in London.
                      > I got it at the Bargain price of £260 new!! (Special offer at the
                      show)
                      > And have to say the build quality is superb.
                      > It is very nearly the Cheapest 'near' APO you can buy with a build
                      quality
                      > better than most of its rivals.
                      > (The colour correction of mine seems to be very good).
                      > I also own a Vixen 103s which is also a very good scope but not
                      built as
                      > solid as the WO range.
                      >
                      > The Sky at Night review gave it an overall score of 95% and the
                      review was
                      > done by Peter Lawrence.
                      > In and out of focus colour correction appears to be good.
                      > Using a DSLR you will get elongation of the Stars near the edges
                      unless you
                      > use a field flattener.
                      > One comment made was they needed to put a tube extender on the M72
                      as it
                      > would not quite make focus (I assume with the DSLR) not uncommon
                      with
                      > Refractors.
                      >
                      > I had a ZS66 SD 2 thing's made me upgrade to the Megrez 72
                      > 1/ 2" focuser
                      > 2/ the same focuser used in the Excellent Megrez 90
                      > More solid and positive than the ZS66 SD.
                      >
                      > HTH,
                      >
                      > --
                      > Paul Gordon
                      > paul@...
                      > http://www.madpc.co.uk
                      >
                      > -----Original Message-----
                      > From: William-Optics@yahoogroups.com [mailto:William-
                      Optics@yahoogroups.com]
                      > On Behalf Of zverjuga2005
                      > Sent: 2008-03-17 04:00
                      > To: William-Optics@yahoogroups.com
                      > Subject: [William Optics] Re: Is Megrez 72FD an APO?
                      >
                      > Hi Suk.
                      > I did not have a chance to look through M72, but I have ZS66.
                      > And ZS66 is a great scope for the price I paid for it (around
                      EUR240).
                      > Maybe if I will compare it with Takahashi FS60C it will be not so
                      > great, but I know that Tak scope will cost me double or triple what
                      > WO telescopes cost.
                      > For example, in Europe M72 costs EUR389 ($580) for OTA.
                      > Takahashi FS60C will be around EUR640 ($960).
                      >
                      > I am happy with ZS66 and for $960 I can buy M90 or M110.
                      >
                      > If you want the best telescope then Tak, AP, TEC will be the right
                      > one. But if you want to safe some money then you should go for WO.
                      >
                      > Another thought: I don't think doublet can be a true APO.
                      >
                      > Few times I used friend's M110 which is doublet too. It has some
                      > color with high power eyepiece. Color correction of M110 is better
                      > then Achromat, but it's not a true APO.
                      > FLT110 is APO, but it costs two times more then M110.
                      >
                      > That's why we always have to think about the price we paid for it.
                      >
                      > Tomas.
                      >
                      > --- In William-Optics@yahoogroups.com, "mirfak30" <mirfak30@>
                      > wrote:
                      > >
                      > > I can "not" say "yes".
                      > >
                      > > Last night, just 11 hours ago in Korea, I was in a mountain
                      > together
                      > > with 9 club members.(Our club name is Seoul Astronomy Club. Seoul
                      > is
                      > > the capital city of Korea) Under the sky of 7~8/10 seeing there
                      > were
                      > > 12 scopes; Takahashi, Pentax, Vixen, Celestron, Skywatcher... so
                      > on.
                      > > Among them really pretty Megrez 72FD with Takahashi FS60C as a
                      > guide
                      > > scope.
                      > >
                      > > It was ready to be tested for visual performance after a few
                      shots
                      > > of imaging. We looked Arcturus through Vixen LV 2.5mm(x173) and
                      saw
                      > > something not expected; fresnel rings full of CA! Even in-focus-
                      > > image looked so much colorful. To make it worse about 1/7 of airy
                      > > disk was fuzzy similar to a tail of a comet. We moved the scope
                      to
                      > > Saturn. And?, same; colorful Saturn. We thought the eyepiece
                      might
                      > > have big problems so we changed it to Takahashi Hi-Le 3.6mm(x120)
                      > > then Pentax XW 7mm and 5mm on 2.5x Powermate (x154 and x216) but
                      > all
                      > > the same; colorful and fuzzy.
                      > >
                      > > Conclusion? FD72 has the problems.
                      > >
                      > > Unfortunately for the 72FD we had Takahashi FS-60 and FS-78. So
                      the
                      > > 72FD gave us bad feeling; a seriously defective optics.
                      > >
                      > > Now what shall we do?
                      > >
                      > > Suk
                      > >
                      >
                      >
                      >
                      > ------------------------------------
                      >
                      > www.williamoptics.com
                      www.williamopticsracing.comYahoo!
                      > Groups Links
                      >
                    • Paul Gordon
                      Hi Tomas, I have to say I have owned the following scopes from William Optics: - 2x ZS66 SD 1x Megrez 90 1x Megrez 110 And now 1x Megrez 72 Discounting the
                      Message 10 of 20 , Mar 18, 2008
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                        Hi Tomas,

                        I have to say I have owned the following scopes from William Optics: -

                        2x ZS66 SD
                        1x Megrez 90
                        1x Megrez 110
                        And now
                        1x Megrez 72

                        Discounting the Megrez 72 as I have only owned it for a few weeks my
                        favourite WO scope has to be the Megrez 90.

                        (I chop and change scopes quite a lot :-))

                        I have also owned the following: -

                        Achromatic Refractors
                        ---------------------
                        1x Skywatcher 80mm
                        1x Skywatcher 120mm
                        1x Tal 100r

                        APO Refractors
                        ----------
                        2x Skywatcher 80ED's
                        2x Skywatcher 100ED's

                        Klevtzov-Cassegrain
                        -------------------
                        1x Tal 200K

                        SCT
                        ---
                        1x Celestron C8
                        1x Celestron C11

                        Maksutov Cassegrains
                        --------------------
                        1x Orion Optics OMC 140
                        1x Orion Optics OMX 250

                        Catadioptric (Visac)
                        ------------
                        1x Vixen VCL200

                        Newtonian
                        ----------
                        1x Tal 110
                        1x Tal 120
                        1x Orion Optics 150mm F5
                        2x Orion Optics 200mm F6
                        1x Orion Optics 200mm F5
                        1x Orion Optics 250mm F4.8
                        1x Orion Optics 250mm F6.3

                        And a few other less well known makes :-)

                        I have settled for the time being on my Vixen 103s and Megrez 72 combo

                        Regards,
                        --
                        Paul Gordon
                        paul@...
                        http://www.madpc.co.uk


                        -----Original Message-----
                        Subject: [William Optics] Re: Is Megrez 72FD an APO?

                        Paul,
                        after your comments i want to upgrade my ZS66 :-)

                        It seems either your scope is better then Suk's M72 or his
                        expectations are too high as he compared it to Tak.

                        Tomas.


                        [Snip]
                      • mirfak30
                        According to the posts here, it seems that my friend was not lucky to buy a good one. (The FD72 is not mine. I have WO ZS110 which has also astigmatism (looks
                        Message 11 of 20 , Mar 18, 2008
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                          According to the posts here, it seems that my friend was not lucky
                          to buy a good one. (The FD72 is not mine. I have WO ZS110 which has
                          also astigmatism (looks like due to pinched optic) and other
                          problems. I sent my ZS110 to Taiwan for repairing.

                          Our(me + my club members) expectation for the FD76 was not so
                          high.^^ We knew its price. The reason why I posted this bad review
                          was the visual performance of the FD72 showed absolute quality
                          problem. (sorry for this straight talk)

                          Yes, its price tells that it should not be compared to Takahashi FS-
                          78. But not so cheap one either. I think that if 72mm U$600 (in
                          Korea U$700) scope shows color in Saturn in x120 it can not be
                          called as Apo. On top of that the in-focus star image was not round.
                          To make it worse collimation looked no problem and no trace of
                          pinched optics. For us this kind of strange result meant that its
                          optics had bad issue

                          Anyway I hope that everybody else would be lucky to choose good
                          ones, no more case of my friend's. (And also no more case of mine
                          with ZS110)

                          Suk


                          --- In William-Optics@yahoogroups.com, "rhofm" <rhofm@...> wrote:
                          >
                          > Abbe's definition of apochromatism was the following: an objective
                          corrected parfocally for
                          > three widely spaced wavelengths and corrected for spherical
                          aberration and coma for two
                          > widely separated wavelengths. Sometimes only the first part of the
                          definition is used to
                          > describe an apochromat.
                          >
                          > For such a small objective a triplet is not necessary. For a 110mm
                          this is different, although
                          > there are good apos with only a doublet.
                          >
                          > Is the 72 an apo? I haven't seen a spot diagram for the 72, so I
                          don't know if it was intended
                          > as one. I have used mine only for a short time and was very
                          pleased with the views, but I've
                          > never used very high magnifications. I bought the telescope as a
                          carry-everywhere widefield
                          > scope for visual and photographic applications and as a
                          guidescope. I was impressed by the
                          > photographic performance for such a relatively cheap and small
                          scope.
                          >
                          > Looking at the forum posts I can see that some were lucky and got
                          a good one, some
                          > weren't.
                          >
                          > -Rainer
                          >
                        • zverjuga2005
                          Suk, If that scope is really faulty then you have to contact your dealer. So far everyone was very positive about this scope. I love my ZS66!!!! Tom. ...
                          Message 12 of 20 , Mar 18, 2008
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                            Suk,
                            If that scope is really faulty then you have to contact your dealer.
                            So far everyone was very positive about this scope.
                            I love my ZS66!!!!

                            Tom.


                            --- In William-Optics@yahoogroups.com, "mirfak30" <mirfak30@...>
                            wrote:
                            >
                            > According to the posts here, it seems that my friend was not lucky
                            > to buy a good one. (The FD72 is not mine. I have WO ZS110 which has
                            > also astigmatism (looks like due to pinched optic) and other
                            > problems. I sent my ZS110 to Taiwan for repairing.
                            >
                            > Our(me + my club members) expectation for the FD76 was not so
                            > high.^^ We knew its price. The reason why I posted this bad review
                            > was the visual performance of the FD72 showed absolute quality
                            > problem. (sorry for this straight talk)
                            >
                            > Yes, its price tells that it should not be compared to Takahashi FS-
                            > 78. But not so cheap one either. I think that if 72mm U$600 (in
                            > Korea U$700) scope shows color in Saturn in x120 it can not be
                            > called as Apo. On top of that the in-focus star image was not
                            round.
                            > To make it worse collimation looked no problem and no trace of
                            > pinched optics. For us this kind of strange result meant that its
                            > optics had bad issue
                            >
                            > Anyway I hope that everybody else would be lucky to choose good
                            > ones, no more case of my friend's. (And also no more case of mine
                            > with ZS110)
                            >
                            > Suk
                            >
                            >
                            > --- In William-Optics@yahoogroups.com, "rhofm" <rhofm@> wrote:
                            > >
                            > > Abbe's definition of apochromatism was the following: an
                            objective
                            > corrected parfocally for
                            > > three widely spaced wavelengths and corrected for spherical
                            > aberration and coma for two
                            > > widely separated wavelengths. Sometimes only the first part of
                            the
                            > definition is used to
                            > > describe an apochromat.
                            > >
                            > > For such a small objective a triplet is not necessary. For a
                            110mm
                            > this is different, although
                            > > there are good apos with only a doublet.
                            > >
                            > > Is the 72 an apo? I haven't seen a spot diagram for the 72, so I
                            > don't know if it was intended
                            > > as one. I have used mine only for a short time and was very
                            > pleased with the views, but I've
                            > > never used very high magnifications. I bought the telescope as a
                            > carry-everywhere widefield
                            > > scope for visual and photographic applications and as a
                            > guidescope. I was impressed by the
                            > > photographic performance for such a relatively cheap and small
                            > scope.
                            > >
                            > > Looking at the forum posts I can see that some were lucky and got
                            > a good one, some
                            > > weren't.
                            > >
                            > > -Rainer
                            > >
                            >
                          • zverjuga2005
                            Paul, You have (had) many great scopes!!! ... Optics: - ... combo
                            Message 13 of 20 , Mar 18, 2008
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                              Paul,
                              You have (had) many great scopes!!!



                              --- In William-Optics@yahoogroups.com, "Paul Gordon" <paul@...> wrote:
                              >
                              > Hi Tomas,
                              >
                              > I have to say I have owned the following scopes from William
                              Optics: -
                              >
                              > 2x ZS66 SD
                              > 1x Megrez 90
                              > 1x Megrez 110
                              > And now
                              > 1x Megrez 72
                              >
                              > Discounting the Megrez 72 as I have only owned it for a few weeks my
                              > favourite WO scope has to be the Megrez 90.
                              >
                              > (I chop and change scopes quite a lot :-))
                              >
                              > I have also owned the following: -
                              >
                              > Achromatic Refractors
                              > ---------------------
                              > 1x Skywatcher 80mm
                              > 1x Skywatcher 120mm
                              > 1x Tal 100r
                              >
                              > APO Refractors
                              > ----------
                              > 2x Skywatcher 80ED's
                              > 2x Skywatcher 100ED's
                              >
                              > Klevtzov-Cassegrain
                              > -------------------
                              > 1x Tal 200K
                              >
                              > SCT
                              > ---
                              > 1x Celestron C8
                              > 1x Celestron C11
                              >
                              > Maksutov Cassegrains
                              > --------------------
                              > 1x Orion Optics OMC 140
                              > 1x Orion Optics OMX 250
                              >
                              > Catadioptric (Visac)
                              > ------------
                              > 1x Vixen VCL200
                              >
                              > Newtonian
                              > ----------
                              > 1x Tal 110
                              > 1x Tal 120
                              > 1x Orion Optics 150mm F5
                              > 2x Orion Optics 200mm F6
                              > 1x Orion Optics 200mm F5
                              > 1x Orion Optics 250mm F4.8
                              > 1x Orion Optics 250mm F6.3
                              >
                              > And a few other less well known makes :-)
                              >
                              > I have settled for the time being on my Vixen 103s and Megrez 72
                              combo
                              >
                              > Regards,
                              > --
                              > Paul Gordon
                              > paul@...
                              > http://www.madpc.co.uk
                              >
                              >
                              > -----Original Message-----
                              > Subject: [William Optics] Re: Is Megrez 72FD an APO?
                              >
                              > Paul,
                              > after your comments i want to upgrade my ZS66 :-)
                              >
                              > It seems either your scope is better then Suk's M72 or his
                              > expectations are too high as he compared it to Tak.
                              >
                              > Tomas.
                              >
                              >
                              > [Snip]
                              >
                            • rhofm
                              ... Hello Suk, I also had problems with my ZS110. I also sent the lens back to Taiwan and got it back after 8 weeks. Don t know if it s good now, the weather
                              Message 14 of 20 , Mar 19, 2008
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                                --- In William-Optics@yahoogroups.com, "mirfak30" <mirfak30@...> wrote:
                                >
                                > According to the posts here, it seems that my friend was not lucky
                                > to buy a good one. (The FD72 is not mine. I have WO ZS110 which has
                                > also astigmatism (looks like due to pinched optic) and other
                                > problems. I sent my ZS110 to Taiwan for repairing.
                                >
                                > Our(me + my club members) expectation for the FD76 was not so
                                > high.^^ We knew its price. The reason why I posted this bad review
                                > was the visual performance of the FD72 showed absolute quality
                                > problem. (sorry for this straight talk)
                                >
                                > Yes, its price tells that it should not be compared to Takahashi FS-
                                > 78. But not so cheap one either. I think that if 72mm U$600 (in
                                > Korea U$700) scope shows color in Saturn in x120 it can not be
                                > called as Apo. On top of that the in-focus star image was not round.
                                > To make it worse collimation looked no problem and no trace of
                                > pinched optics. For us this kind of strange result meant that its
                                > optics had bad issue
                                >
                                > Anyway I hope that everybody else would be lucky to choose good
                                > ones, no more case of my friend's. (And also no more case of mine
                                > with ZS110)
                                >
                                > Suk

                                Hello Suk,

                                I also had problems with my ZS110. I also sent the lens back to Taiwan and got it back
                                after 8 weeks. Don't know if it's good now, the weather has been bad the last three weeks.
                                reading this forum (and some others) it seems WO might have a problem with quality
                                control.

                                Best regards,
                                Rainer
                              • tonyw90
                                With respect to previous posts I have just had first light with my FD72. From the outskirts of Liverpool UK using 20x mag. the view of the almost Full Moon was
                                Message 15 of 20 , Mar 19, 2008
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                                  With respect to previous posts I have just had first light with my
                                  FD72. From the outskirts of Liverpool UK using 20x mag. the view of
                                  the almost Full Moon was crisp and tack sharp with no colour fringes
                                  around the limb. At 40x with a 50% neutral density filter the view was
                                  just as sharp.
                                  Turning to Saturn at 40x there was no apparent colour abberation but
                                  at 20x there was some coma effect when placing the planet off center
                                  but I would imagine this would be negated by the use of a 0.8 focal
                                  reducer/field flattener.
                                  I intend to take this scope to China next year to view the eclipse and
                                  will be using my Vixen VX1 astro camera (yes, real film!) to record it.
                                  My next purchase will be a WO camera adaptor and if I could buy some
                                  dark skies now I would go for that too! I'll then piggyback the FD72
                                  on my 10" Newt. for some wide field astrophotography. Hopefully I'll
                                  have some results worth posting in the future!
                                  Regards and clear skies to all.

                                  Tony
                                • mirfak30
                                  Good day Rainer, I have not got my ZS-110 back yet from Taiwan. I sent it to Taiwan one month ago and there have been some stroies and still in Taiwan. I hope
                                  Message 16 of 20 , Mar 19, 2008
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                                    Good day Rainer,

                                    I have not got my ZS-110 back yet from Taiwan. I sent it to Taiwan
                                    one month ago and there have been some stroies and still in Taiwan.
                                    I hope it comes back to me next week

                                    It will be appreciated that you put a post here after checking the
                                    result of reparing.

                                    I agree that it seems WO might have some problems with quality
                                    control, better than some of Chinese origins though.
                                    Another friend of mine has ZS-105 with the same problems as mine.

                                    Best Regards,


                                    Suk



                                    >
                                    > I also had problems with my ZS110. I also sent the lens back to
                                    Taiwan and got it back
                                    > after 8 weeks. Don't know if it's good now, the weather has been
                                    bad the last three weeks.
                                    > reading this forum (and some others) it seems WO might have a
                                    problem with quality
                                    > control.
                                    >
                                    > Best regards,
                                    > Rainer
                                    >
                                  • rhofm
                                    ... Hello Suk, I shall post a report when I have some reults. Unfortunately the weather report doesn t look good for the next week. Best regards, Rainer
                                    Message 17 of 20 , Mar 21, 2008
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                                      --- In William-Optics@yahoogroups.com, "mirfak30" <mirfak30@...> wrote:
                                      >
                                      > Good day Rainer,
                                      >
                                      > I have not got my ZS-110 back yet from Taiwan. I sent it to Taiwan
                                      > one month ago and there have been some stroies and still in Taiwan.
                                      > I hope it comes back to me next week
                                      >
                                      > It will be appreciated that you put a post here after checking the
                                      > result of reparing.
                                      >
                                      > I agree that it seems WO might have some problems with quality
                                      > control, better than some of Chinese origins though.
                                      > Another friend of mine has ZS-105 with the same problems as mine.
                                      >
                                      > Best Regards,
                                      >
                                      >
                                      > Suk
                                      >

                                      Hello Suk,

                                      I shall post a report when I have some reults. Unfortunately the weather report doesn't
                                      look good for the next week.

                                      Best regards,
                                      Rainer
                                    • davidrossitter2000
                                      Hi I am just about to buy one of these both as a widefield for my St2000XM camera (assume Ill need a focal reducer with this setup) and a terrestrial spotting
                                      Message 18 of 20 , Mar 22, 2008
                                      • 0 Attachment
                                        Hi

                                        I am just about to buy one of these both as a widefield for my
                                        St2000XM camera (assume Ill need a focal reducer with this setup) and
                                        a terrestrial spotting scope. I had read the cloudy nights review
                                        which seemed very positive but having seen this thread I am less sure
                                        now. Any further experiences good or bad on this scope - or my
                                        intended set up?

                                        I have a bigger TMB APO (130 f6) and a Meade 14" for the narrow
                                        fields/higher magnification stuff.

                                        Thanks David

                                        --- In William-Optics@yahoogroups.com, "mirfak30" <mirfak30@...>
                                        wrote:
                                        >
                                        > According to the posts here, it seems that my friend was not lucky
                                        > to buy a good one. (The FD72 is not mine. I have WO ZS110 which has
                                        > also astigmatism (looks like due to pinched optic) and other
                                        > problems. I sent my ZS110 to Taiwan for repairing.
                                        >
                                        > Our(me + my club members) expectation for the FD76 was not so
                                        > high.^^ We knew its price. The reason why I posted this bad review
                                        > was the visual performance of the FD72 showed absolute quality
                                        > problem. (sorry for this straight talk)
                                        >
                                        > Yes, its price tells that it should not be compared to Takahashi FS-
                                        > 78. But not so cheap one either. I think that if 72mm U$600 (in
                                        > Korea U$700) scope shows color in Saturn in x120 it can not be
                                        > called as Apo. On top of that the in-focus star image was not
                                        round.
                                        > To make it worse collimation looked no problem and no trace of
                                        > pinched optics. For us this kind of strange result meant that its
                                        > optics had bad issue
                                        >
                                        > Anyway I hope that everybody else would be lucky to choose good
                                        > ones, no more case of my friend's. (And also no more case of mine
                                        > with ZS110)
                                        >
                                        > Suk
                                        >
                                        >
                                        > --- In William-Optics@yahoogroups.com, "rhofm" <rhofm@> wrote:
                                        > >
                                        > > Abbe's definition of apochromatism was the following: an
                                        objective
                                        > corrected parfocally for
                                        > > three widely spaced wavelengths and corrected for spherical
                                        > aberration and coma for two
                                        > > widely separated wavelengths. Sometimes only the first part of
                                        the
                                        > definition is used to
                                        > > describe an apochromat.
                                        > >
                                        > > For such a small objective a triplet is not necessary. For a
                                        110mm
                                        > this is different, although
                                        > > there are good apos with only a doublet.
                                        > >
                                        > > Is the 72 an apo? I haven't seen a spot diagram for the 72, so I
                                        > don't know if it was intended
                                        > > as one. I have used mine only for a short time and was very
                                        > pleased with the views, but I've
                                        > > never used very high magnifications. I bought the telescope as a
                                        > carry-everywhere widefield
                                        > > scope for visual and photographic applications and as a
                                        > guidescope. I was impressed by the
                                        > > photographic performance for such a relatively cheap and small
                                        > scope.
                                        > >
                                        > > Looking at the forum posts I can see that some were lucky and got
                                        > a good one, some
                                        > > weren't.
                                        > >
                                        > > -Rainer
                                        > >
                                        >
                                      • rhofm
                                        Hello Suk, yesterday I was able to check my repaired lens. Seeing was horrible so I couldn t make a proper star test, but I made some photos and it seems that
                                        Message 19 of 20 , Mar 31, 2008
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                                          Hello Suk,

                                          yesterday I was able to check my repaired lens. Seeing was horrible so I couldn't make a
                                          proper star test, but I made some photos and it seems that the problem with the asymetric
                                          spikes has been fixed.

                                          Best regards,
                                          Rainer

                                          --- In William-Optics@yahoogroups.com, "mirfak30" <mirfak30@...> wrote:
                                          >
                                          > Good day Rainer,
                                          >
                                          > I have not got my ZS-110 back yet from Taiwan. I sent it to Taiwan
                                          > one month ago and there have been some stroies and still in Taiwan.
                                          > I hope it comes back to me next week
                                          >
                                          > It will be appreciated that you put a post here after checking the
                                          > result of reparing.
                                          >
                                          > I agree that it seems WO might have some problems with quality
                                          > control, better than some of Chinese origins though.
                                          > Another friend of mine has ZS-105 with the same problems as mine.
                                          >
                                          > Best Regards,
                                          >
                                          >
                                          > Suk
                                          >
                                          >
                                          >
                                          > >
                                          > > I also had problems with my ZS110. I also sent the lens back to
                                          > Taiwan and got it back
                                          > > after 8 weeks. Don't know if it's good now, the weather has been
                                          > bad the last three weeks.
                                          > > reading this forum (and some others) it seems WO might have a
                                          > problem with quality
                                          > > control.
                                          > >
                                          > > Best regards,
                                          > > Rainer
                                          > >
                                          >
                                        • mirfak30
                                          Good day Rainer, I also received ZS110 last Friday, and last night I drove my car for 1 hour to the observing site. As like you seeing was so terrible though,
                                          Message 20 of 20 , Mar 31, 2008
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                                            Good day Rainer,

                                            I also received ZS110 last Friday, and last night I drove my car for
                                            1 hour to the observing site. As like you seeing was so terrible
                                            though, it seemed that pinched astigmatic image did not appear.

                                            When seeing becomes good let's check it again.

                                            Thank you


                                            Suk





                                            --- In William-Optics@yahoogroups.com, "rhofm" <rhofm@...> wrote:
                                            >
                                            > Hello Suk,
                                            >
                                            > yesterday I was able to check my repaired lens. Seeing was
                                            horrible so I couldn't make a
                                            > proper star test, but I made some photos and it seems that the
                                            problem with the asymetric
                                            > spikes has been fixed.
                                            >
                                            > Best regards,
                                            > Rainer
                                            >
                                            > --- In William-Optics@yahoogroups.com, "mirfak30" <mirfak30@>
                                            wrote:
                                            > >
                                            > > Good day Rainer,
                                            > >
                                            > > I have not got my ZS-110 back yet from Taiwan. I sent it to
                                            Taiwan
                                            > > one month ago and there have been some stroies and still in
                                            Taiwan.
                                            > > I hope it comes back to me next week
                                            > >
                                            > > It will be appreciated that you put a post here after checking
                                            the
                                            > > result of reparing.
                                            > >
                                            > > I agree that it seems WO might have some problems with quality
                                            > > control, better than some of Chinese origins though.
                                            > > Another friend of mine has ZS-105 with the same problems as mine.
                                            > >
                                            > > Best Regards,
                                            > >
                                            > >
                                            > > Suk
                                            > >
                                            > >
                                            > >
                                            > > >
                                            > > > I also had problems with my ZS110. I also sent the lens back
                                            to
                                            > > Taiwan and got it back
                                            > > > after 8 weeks. Don't know if it's good now, the weather has
                                            been
                                            > > bad the last three weeks.
                                            > > > reading this forum (and some others) it seems WO might have a
                                            > > problem with quality
                                            > > > control.
                                            > > >
                                            > > > Best regards,
                                            > > > Rainer
                                            > > >
                                            > >
                                            >
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