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20344Re: Need focal reducer help!

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  • uwpf23
    Dec 2, 2003
      Thanks Mark. I think I'm going to use a Celestron ST80 guide
      scope mounted piggyback for the larger objects (with the AO-7
      removed), and use the .63 reducer/AO-7 with the C-14 the rest of the
      time. Appreciate the help from everybody who responded!

      Clear skies,
      Wade
      ///////////////////////////////////////////////////////////////////

      --- In ccd-newastro@yahoogroups.com, "Mark de Regt" <deregt@e...>
      wrote:
      > You can't use a Meade .33 reducer with the AO-7--the distance is
      too great
      > from reducer to chip, and you won't be able to focus (even if you
      could, the
      > distortion would be horrible).
      >
      > The .63 reducer should work; it does with my LX200 with an AO-7.
      I don't
      > know about the optec filters, except that I understand that they
      will not
      > work with the CFW-8.
      >
      > Mark de Regt
      > Redmond, Washington, USA
      > 47.7 N. Latitude; 122 West Longitude
      > Astro Images: http://home.earthlink.net/~akilla/MAD
      >
      >
      >
      >
      > > -----Original Message-----
      > > From: uwpf23 [mailto:uwpf23@y...]
      > > Sent: Sunday, November 30, 2003 8:29 PM
      > > To: ccd-newastro@yahoogroups.com
      > > Subject: [ccd-newastro] Need focal reducer help!
      > >
      > >
      > > Hi,
      > > I cannot achieve focus with a Meade F/3.3 focal reducer used with
      > > the following:
      > > 1) Celestron CGE-1400 OTA. 3910mm focal length @ F-11 when no
      focal
      > > reducer used.
      > > 2) CCD setup is an ST-7/CFW-8/AO-7 all attached together.
      > > 3) JMI SmartFocus elecric micro-focuser.
      > >
      > > I've tried the following already:
      > > 1) Mounted the reducer directly onto the visual back of the OTA
      first,
      > > then attached the JMI, then the CCD gear. Racked the Celestron
      > > main focus knob all the way clockwise (mirror moved all the
      way
      > > back toward the rear). The image was moving toward focus, but
      > > could not get all the way focused.
      > > 2) Mounted JMI focuser first, then the reducer, then the CCD
      gear.
      > > Same result.
      > >
      > > Note: I CAN get focus with the F/3.3 reducer through the
      eyepiece and
      > > a star diagonal visually (NO CCD attached).
      > >
      > > Is my problem that the focal reducer lens is too far away from
      the
      > > CCD chip with all the gear attached? Or, is it too close to the
      CCD
      > > chip? It seems from the visual eyepiece check that the reducer
      is
      > > too far away from the CCD chip. I can't get it any closer
      without
      > > removing some of the CCD attachments, which is not feasible for
      me
      > > (can't do without the color wheel or adaptive optics).
      > >
      > > Anybody have any ideas on what the cure for this is? If this
      specific
      > > focal reducer is incompatible, anybody have any suggestions for
      brands
      > > that will work and are faster than F/6.3 (already have a .63 from
      > > Celestron that works fine--just need shorter focal lengths than
      this
      > > with such a long main focal length to work with!). Would like
      to get
      > > down to at least F/4 or 4.5 if possible, as F/6.3 just is not
      > > desirable with some objects on the CGE-1400.
      > >
      > > Thanks for any help you all can give me on this!
      > >
      > > Clear skies,
      > > Wade Van Arsdale
      > > Little Rock, AR.
      > > (Registered NewAstro Customer)
      > >
      > >
      > >
      > >
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      > > ccd-newastro-unsubscribe@egroups.com
      > >
      > >
      > >
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      > >
      > >
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