Pin-sharp accurate polar alignment

I'm looking for an easy to follow guide on achieving very accurate polar alignment for my Celestron CGE equatorial mount for long-exposure photography.

Has anybody come across such a guide online?

How do our astrophotography experts online here achieve such accurate polar alignment? Do you use cross-hair eyepieces or other techniques?

Please excuse my ignorance, this is a new area for me.

thanks!

For me, from read and listening to what others have told me, my guess is using a guidescope technique. This uses a smaller scope mounted on your main one. Each has a camera attached. However, the smaller Guidescope's camera is connected to some software which, when focused on a star, will ensure that the guidescope is fixed on that star. In turn, if it starts to drift, the software makes some corrections to the mount motors to keep it fixed in the centre of the field of view. Thus, the main scope's CCD can keep fixed on the intended object longer. The computations are pretty much ongoing to ensure lack of any significant drift.

I can't give you pro's and cons, although one that does come to mind is that you need a decent star in the field of view of the Guidescope, so if you're looking at a faint starfield, then it might pose a small allignment problem, but the chances of looking at an area of sky with no prominent star to be seen is very slim, no matter how small the field of view.

Hope this gives you some ideas Keith.

Seanie.

Keith,

If you have access to a CCD camera, there are various tricks one can use to get super duper accurate polar alignment.

For example:

(1) www.ucihs.uci.edu/pandb/hall/polar.htm ... very similar to using an eyepiece with crosshairs but now with a CCD

(2) users.bsdwebsolutions.com/~larryweber/ ... my favourite - I am within 4 arc-seconds of the pole for both axes

(3) www.ccdware.com/products/pempro/ ... great program for correcting PEC and also polar aligning

Seanie - I think you answered a different question...

Keith - I use the drift-align technique combined with the CCD camera. Just Google "polar drift align" and I'm sure you'll all the necessary hits - see which seems the best explained for you.

Anthony - I have used PAM and to be honest, I have always done better using the drift method. I think PAM would get you very close if you were misaligned by a fair few arcmins - but for me drift gets me within arcsecs of the pole.

Dave

Hi Dave,

No question the drift method is very effective and it is something which I had used for a long time.

My only criticism is that it can be time consuming and especially as you approach closer and closer to good alignment.

Anthony,
The last time I looked at Polealignmax, it needed Pinpoint. If I understand correctly, The Sky will now suffice and there is no need for Pinpoint. Is that correct?