Quote:

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You could think so but most people will not bother to do a simple test to verify somebody's assertion. I did verify it. I suggest you do the same.

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What did you verify? I read the thread you referred to and as far as I can tell, it's just an assertion at this point. Here's the comment from the thread:

"The GOTO to a
polar alignment star initiated from the `Polar Align / Align Mount' menu item
puts the star in a different location than the GOTO initiated from the Named
Star list or the SAO list."

Yes, I've also noticed that, but I can also verify that regardless of the discrepancy my polar alignment is very accurate, at least accurate enough for me to image at 320mm f/l with 2 minutes exposures over a period of an hour and have almost no field rotation. Since I'm shooting at such short focal lengths, polar alignment errors show up as stars moving from frame to frame even when star trails are not evident. Even when I was doing drift aligning, it was still not perfect and I had frame to frame field rotation.

Therefore, I think the polar alignment portion is pretty good (and perhaps better than I was getting with a drift alignment) whether the coordinates are off or not. At this point, I tend to think it more a lack of understanding of how the system works, but I could be wrong...been there before...many times.

After doing the ASPA, the initial goto alignment stars should be replaced since the mount was moved manually, which should refresh the goto alignment.

Patrick

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10" f/6 Truss Tube Newtonian
Celestron C6S-GT SCT
AT66ED Refractor
Oberwerk Ultra 15x70 Binocular
475B Geared Tripod & 501HDV Head
Celestron Regal 8x42 Binocular
Canon XSi; Meade DSI;SPC900-NC
Vixen GP2 Photo Guider Mount


My Astronomy Pages

Edited by Patrick (10/26/09 10:04 AM)

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