RE: Scope City Story - LX200 GPS 12 & NexStar 11 GPS

From: David Samuels (david.samuels@No-Spam)
Date: Thu Apr 17 2003 - 13:03:03 MST

  • Next message: Paul Sterngold: "Re: RE: Scope City Story - LX200 GPS 12 & NexStar 11 GPS"

    >In general, if I had to do it all again, for the purposes of
    astrophotography, I wouldn't buy a new scope off either of these companies.
    I'd buy a great third party mount (G11/Gemini, AP, etc - there are now many
    great mounts on the market), and buy a smaller faster OTA to start, *maybe*
    some day buying a used SCT OTA (C8 probably). SCT's are not great beginner
    CCD OTA's. They require a lot of accuracy in tracking and guiding, have big
    focus shift problems, and tend to have very small fields with the average
    beginner to intermediate chips.

    Are you saying that a SCT is bad for the job or bad for newbies? I am
    learning that a german eq mount doesn't have a problem pointing at 90
    degrees up from the base while cameras and things are attached - the
    fork-mounted SCT can't.

    You say that an SCT is a bad beginner CCD OTA - due to accuracy, tracking,
    guiding, focus shift, small fields of view. Isn't the lens speed resolved
    with f/6.3 or f/3.3 reducers/field flatteners? The LX200 has a primary
    mirror lock and microfocuser. Would that be sufficient to solve the focus
    shift problems. As far as tracking and guiding goes, if it works within
    spec, are there still tracking and guiding issues? What issues are those?
    How do SCT owners resolve them?

    Thanks for the input.

    Dave



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