Computerised polar alignment: Celestron v Meade

Gem (Grant) · #1 09-05-2011, 11:42 PM

Hi

Celestron (e.g. CGEM) have their "all star" polar alignment feature. No need to drift align.
Is the Meade "3 star high precision" polar alignment (e.g. LXD 75) similar? Is this a true polar alignment or just a GOTO alignment?
Please, no comments as to "learning to drift align"! I am wanting to understand the features of the mounts so as to make an informed purchase.

THANKS!

barx1963 (Malcolm) · #2 09-05-2011, 11:46 PM

I did ask a Celestron dealer about the Celestron polar alignment, he indicated that it was OK for visual use, but needed to be fine tuned for imaging. Of course he also sai he didn't know much about it which was a small worry!

Malcolm

Gem (Grant) · #3 10-05-2011, 07:11 AM

I have heard from users that it is ok if you use several stars. The question for me is: is the Meade feature the same or is it something different?

graham.hobart (Graham stevens) · #4 10-05-2011, 08:37 AM

The Meade polar align routine (at least for LX 90) is a three star/two star/ or one star routine which tries to accurately get a picture of the sky in polar config. So it is necessary to have an idea of where the stars are and a clear-ish sky. I have found that for visual use two stars is enough but not for photography
Graham

graham.hobart (Graham stevens) · #5 10-05-2011, 09:03 AM

So I think the Meade is precision GOTO alignment. I don't know about the All star Celestron polar alignment but I have heard good things about it.

mithrandir (Andrew) · #6 10-05-2011, 09:28 AM

Celestron's works by you building a model so it has some idea of you alignment error. You goto a star in its catalog not too far south (north for those on the wrong side of the equator) and not too close to the meridian. Then use the polar adjustment in the Align menu. It slews the scope to where the star should be and you adjust the mount (ie not using the handpiece) to centre the star.

You then rebuild the model, and can repeat the process if you like.

I was never happy with my CG5 for photography, but this works fine for visual. I bought a G11.

A CGEM works better than the CG5. A CGEPro better still.

Andrew

Gem (Grant) · #7 10-05-2011, 09:39 AM

Thanks Andrew. That confirms my understanding of the CGEM. Are there similar features on other brands, or is Celestron the only one with this type of feature?