[jase (Jason)]

A mount with the lowest possible PE should be the starting point. AO is simply trying to counteract the affects of seeing to provide higher resolution images. It’s not meant to correct poor tracking, polar alignment or bad PE – while it will do this to an extent, it should not be depended upon.

Ultimately, what you want to be able to achieve is minimal guiding corrections. Everytime a correction is made, there is room for error. If you have a mount that is precisely polar aligned and tracks reasonably well, guiding corrections are kept to a minimum and you’ll be well on your way in the quest of pinpoint stars.

As Fred mentions, pempro can go greatly assist in PE correction. I’ve used pempro for about two years now and have redefined my PE at different stages. There is still room for improvement on the Losmandy Titan – a peak to peak PE of 2.34 arcsecs is ok, but could be considerably better. My intention is to get this down to around 1.7 arcsecs which I feel is still quite achievable. I may swap the DEC and RA worms to see if I get any further improvements.

You will note the first attachment shows a PE of around +/- 5.0 arcsecs, the second attachment shows the PE curve of 2.34 arcsecs. I measured the X/Y telescope axis error in MaximDL when guiding (at 4 second exposure times) which is shown in the third attachment. I will remeasure PE in pempro next clear night.