Wednesday, September 13, 2006

reference circle demystified

After all this time, I finally realised, the Meade Polaris Reference Circle I bought shortly after I got my telescope (almost 15 years ago), is wrong...

It's wrong in the sense that it is backwards. It is designed to present a view as seen through a telescope with a mirror diagonal. It presents a view where up is up but left is right, a laterally-inverted or mirror-reversed view. It's taken me all this time to figure that out.

And, with irony, I realised that this view does not suit or match the view produced by the simple refractor finder scope built into my Super Polaris German Equatorial Mount. This small scope simply rotates the view, up is down, left is right.

I refired Adobe Illustrator and applied a few changes.



Voila!

I have a reference circle or plate now that shows a "natural" or naked-eye presentation of the North Celestial Pole in relation to Polaris.

And by simply turning the whole plate upside-down, I will be able to mimic the apparent positions of NCP and Polaris as seen in the Polaris finder scope.

What an ordeal...

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