Loading ...
Sorry, an error occurred while loading the content.

Re: just updated Megrez80II to ED triplet

Expand Messages
  • williamoptics2004
    ... ... Hi, The lens purchase is not ready for North America and Europe (suggest retail price is $350), the OTA ($798) will start delivery in
    Message 1 of 8 , Aug 6 4:40 PM
    • 0 Attachment
      --- In William-Optics@yahoogroups.com, "scopacanoe" <scopacanoe@h...>
      wrote:
      > --- In William-Optics@yahoogroups.com, "biuliuming"
      <biuliuming@y...>
      > wrote:
      > > for detail, visit the link:
      > > http://www.astronomy.com.cn/bbs/showthread.php?
      > > s=c863a344a277f7dec26d8a9aca3a0eb2&threadid=26879&pagenumber=2
      >
      > What was the cost of the lens purchase in US dollars??
      > Do you know if this option is being made available in Norht America?
      >
      > thanks,
      > SS

      Hi,

      The lens purchase is not ready for North America and Europe (suggest
      retail price is $350), the OTA ($798) will start delivery in Sep 2004.

      Thank you.

      William
    • no_names_remain99
      Liu- I am in the process of this upgrade. But I m now concerned that inserting a 2-inch extension tube will limit the field and cause some distortion. I have a
      Message 2 of 8 , Aug 16 1:45 AM
      • 0 Attachment
        Liu-

        I am in the process of this upgrade. But I'm now concerned that
        inserting a 2-inch extension tube will limit the field and cause some
        distortion. I have a 44mm Field stop on one eyepiece, with my Megrez
        II it was fully illuminated and the edge was good, but I can't figure
        out how that light cone will handle another two inches of 2 inch
        tubing. Since the origonal tube was designed to have the light cone
        deposited two inches ahead of where it would be with the extension
        tube wouldn't the light entering the extended tube portion get cut
        off at the edges by the tube shaft?
        Have you noticed any vignetting with the two inch extender when used
        with Wide Field 2-inch eyepieces or when taking images?

        -Chris

        --- In William-Optics@yahoogroups.com, "biuliuming" <biuliuming@y...>
        wrote:
        > Kept my old Megrez 80II tube and bought the new ED triplet lens
        > (F/7) from WO, a two inch extender tube is needed to provide enough
        > back focus. The service of WO is quite good and speedy.
        >
        > 1. the lens coating is much better than my old megrez 80 II, the
        > reflection is same as that of Fujinon's EBC(electron bombardment
        > coating) coated lens. Not sure if the coating quality is
        consistent,
        > I hope it does not vary from batch to batch.
        >
        > 2.color correction: much better than megrez 80 II, can be easily
        > pushed to 160 X (2 D) with trace green halo discernable. Even at
        336
        > X, the image of high contrast object didn't break down.
        >
        > 3. Vega shows a little bit halo at 140 X, double-double at lyra is
        > cleanly split at this power, which is no easy for my old megrez 80
        > II.
        >
        > http://www.astronomy.com.cn/bbs/showthread.php?
        > s=&postid=217037#post217037
        >
        > for detail.
        >
        > Liu Ming
        >
        > from Singapore
      • biuliuming
        Dear Chris, I think you are right. I am also having this concern. Before I got the new lens, I was thinking of DIY one extention tube that can be used in front
        Message 3 of 8 , Aug 16 7:34 PM
        • 0 Attachment
          Dear Chris,

          I think you are right.

          I am also having this concern. Before I got the new lens, I was
          thinking of DIY one extention tube that can be used in front of the
          crayfold focuser.

          I have an University Optics' MK70 40mm Konig eyepiece that boasts 70
          deg. AFV, I tried it many times on megrez 80 II and the updated one.
          No vignetting and narrowing of sight was found for naked-eye
          observing.

          Again on the color correction, I'd like to confirm the ED triplet
          one is much better than megrez 80II, 160 folds of power (2 D in mm)
          is easy with images staying clear. At this power, (trace + tight)
          green halo can be seen around white fluorescent lamp and mercury
          lamp, but yellow sodium lamp shows no color fringe, the edges are
          cleaner and sharper.

          Liu
          --- In William-Optics@yahoogroups.com, no_names_remain99
          <no_reply@y...> wrote:
          > Liu-
          >
          > I am in the process of this upgrade. But I'm now concerned that
          > inserting a 2-inch extension tube will limit the field and cause
          some
          > distortion. I have a 44mm Field stop on one eyepiece, with my
          Megrez
          > II it was fully illuminated and the edge was good, but I can't
          figure
          > out how that light cone will handle another two inches of 2 inch
          > tubing. Since the origonal tube was designed to have the light
          cone
          > deposited two inches ahead of where it would be with the extension
          > tube wouldn't the light entering the extended tube portion get cut
          > off at the edges by the tube shaft?
          > Have you noticed any vignetting with the two inch extender when
          used
          > with Wide Field 2-inch eyepieces or when taking images?
          >
          > -Chris
        • no_names_remain99
          Liu- That s great to hear :) I wrote William and he also confirmed that there was no vignetting. I m really looking forward to this new/improved scope. The 5
          Message 4 of 8 , Aug 18 12:12 AM
          • 0 Attachment
            Liu-

            That's great to hear :) I wrote William and he also confirmed that
            there was no vignetting. I'm really looking forward to this
            new/improved scope. The 5 degree field with the UO 40 MK70 must be
            very nice, I'll likely pick up one of these for the Megrez if I end
            up desiring a larger field then my 30mm WSIII can provide.

            Thanks for the post.

            -Chris

            --- In William-Optics@yahoogroups.com, "biuliuming" <biuliuming@y...>
            wrote:
            > Dear Chris,
            >
            > I think you are right.
            >
            > I am also having this concern. Before I got the new lens, I was
            > thinking of DIY one extention tube that can be used in front of the
            > crayfold focuser.
            >
            > I have an University Optics' MK70 40mm Konig eyepiece that boasts
            70
            > deg. AFV, I tried it many times on megrez 80 II and the updated
            one.
            > No vignetting and narrowing of sight was found for naked-eye
            > observing.
            >
            > Again on the color correction, I'd like to confirm the ED triplet
            > one is much better than megrez 80II, 160 folds of power (2 D in mm)
            > is easy with images staying clear. At this power, (trace + tight)
            > green halo can be seen around white fluorescent lamp and mercury
            > lamp, but yellow sodium lamp shows no color fringe, the edges are
            > cleaner and sharper.
            >
            > Liu
            > --- In William-Optics@yahoogroups.com, no_names_remain99
            > <no_reply@y...> wrote:
            > > Liu-
            > >
            > > I am in the process of this upgrade. But I'm now concerned that
            > > inserting a 2-inch extension tube will limit the field and cause
            > some
            > > distortion. I have a 44mm Field stop on one eyepiece, with my
            > Megrez
            > > II it was fully illuminated and the edge was good, but I can't
            > figure
            > > out how that light cone will handle another two inches of 2 inch
            > > tubing. Since the origonal tube was designed to have the light
            > cone
            > > deposited two inches ahead of where it would be with the
            extension
            > > tube wouldn't the light entering the extended tube portion get
            cut
            > > off at the edges by the tube shaft?
            > > Have you noticed any vignetting with the two inch extender when
            > used
            > > with Wide Field 2-inch eyepieces or when taking images?
            > >
            > > -Chris
          • biuliuming
            Well, let me say something about UO 40 MK70. First of all, you need to use 2 star diagonal to get good results, 2 erecting prism may not provide enough
            Message 5 of 8 , Aug 18 8:59 PM
            • 0 Attachment
              Well, let me say something about UO 40 MK70. First of all, you need
              to use 2" star diagonal to get good results, 2" erecting prism may
              not provide enough aperture. Second, due to the improved Konig
              design, the MK70 does show some image aberration on periphery (even
              TV Nagler suffers), pin-point star field is within 70% of the AFV.
              Anyway, the overall experience is very impressive! Finally, MK70
              needs plenty back-focus, so for your upgrading, you must buy the 2"
              extension tube.

              Liu
              --- In William-Optics@yahoogroups.com, no_names_remain99
              <no_reply@y...> wrote:
              > Liu-
              >
              > That's great to hear :) I wrote William and he also confirmed
              that
              > there was no vignetting. I'm really looking forward to this
              > new/improved scope. The 5 degree field with the UO 40 MK70 must be
              > very nice, I'll likely pick up one of these for the Megrez if I
              end
              > up desiring a larger field then my 30mm WSIII can provide.
              >
              > Thanks for the post.
              >
              > -Chris
            Your message has been successfully submitted and would be delivered to recipients shortly.