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  1. #1
    G.T.'s Avatar
    G.T. Guest

    Default Celestron CG-4 or Orion EQ-3 polar axis question



    Ok, when I bought my girlfriend's telescope I decided to dive into the
    complexities of an equatorial mount. I basically understand all the
    concepts but am getting totally thrown off when aligning the polar finder.
    I've used both the Celestron and Orion instructions (the Orion instructions
    are much more thorough) but something just isn't right, I assume it's me.

    Per the instructions I zero and lock the RA circle and zero the date circle.
    I then rotate the mount to either March 1 at 4pm or Oct 10 at 1am. I then
    turn the polar finder until the small Polaris circle in the reticle is at
    the very bottom. Ok, all is good. This matches what Celestron's TheSky
    software show's for Polaris for those dates and times except reversed.

    But then when I rotate the mount to match my current date and time the
    results seem to sometimes be way off according to where Polaris is according
    to TheSky software.

    For instance if I fire off TheSky software for tonight at 8pm Polaris is
    showing directly below the celestial pole.

    I go to the mount, adjust 2 degrees for my current longitude in Los Angeles,
    then rotate the mount until July 9 on the date circle matches 20 hr on the
    RA circle. And the Polaris circle is at the bottom. But that is180 degrees
    off, it should be close to the opposite of Oct 10 at 1 am according to
    TheSky.

    What am I doing wrong? Even if this mount is cheap we're only dealing with
    circles here and the quality isn't so bad that something would be off by 180
    degrees.

    Thanks for any advice.

    Greg



  2. #2
    Paul Buglass's Avatar
    Paul Buglass Guest

    Default Celestron CG-4 or Orion EQ-3 polar axis question

    Hi Greg,

    I gave up trying to work out the details of the time and date rings and use
    a great piece of freeware called "Polar Finder".

    It generates a view of what you should see through the Polar Scope, and you
    simply rotate the RA axis to match, and centre Polaris in the small circle
    and you are done. It works every time, assuming you have taken the time to
    collimate the polar scope with the mount axis first :-).

    A Google search for "Polarfinder" (no space) will bring you :-

    http://arnholm.org/astro/polar_alignment/

    out of many sites which show how to use it and download the free s/w.

    Hope this helps you.

    Very best wishes and clear, dark skies.

    --

    /Paul B, York, UK.
    http://homepages.tesco.net/paul.buglass/astrohome.htm
    York Astronomical Society
    www.yorkastro.co.uk


    "G.T." <getnews1@dslextreme.com> wrote in message
    news:11d06222p597o4c@corp.supernews.com...
    instructions
    circle.
    according
    Angeles,
    degrees
    with
    180



  3. #3
    G.T.'s Avatar
    G.T. Guest

    Default Celestron CG-4 or Orion EQ-3 polar axis question


    "Paul Buglass" <paul.removethisandthisbuglassalsothis@tesco.net > wrote in
    message news:fCWze.5580$GV6.2565@newsfe7-win.ntli.net...
    use
    you
    to

    Thanks. Looking for free software was the next thing I was going to do.

    Greg



 

 

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