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PA and PHD2

Posted: Mon Jun 04, 2018 11:07 pm
by Chuck
My question is about obtaining an "Excellant" PA via SharpCap. I have gotten pretty good at bringing the two parallel lines together and obtaining an excellent PA..............howerver....then when I start to guide via PHD2 and utilize the Guiding Assistant, the GA always informs me that the PA error is 5 arcmin or more sometimes. I don't understand it and it leaves me fairly confused as to what is correct.....PHD2 or SharpCap. Thanks for any help on this issue.

Re: PA and PHD2

Posted: Mon Jun 04, 2018 11:15 pm
by Chuck
I just saw the losing Polar Alignment thread that talks about the same issue that I am having......I have not bumped the mount and everything is nice and tight, including the knob that holds the mount to the tripod. This issue happens every imaging session.

Re: PA and PHD2

Posted: Tue Jun 05, 2018 12:44 am
by cuivenion
If you're on grass your tripod might be sinking. You have to make sure it's well bedded into the ground before putting your scope and weights on.

Re: PA and PHD2

Posted: Tue Jun 05, 2018 1:07 am
by oopfan
This past weekend I watched a YouTube video produced by PHD2 that talked about their polar alignment feature in great detail. The thing that struck me was their use of the term "cone error". I know what cone error is, and I know that Robin knows what it is. I would be shocked if SharpCap's Polar Alignment function did not account for cone error. So what I am suggesting is that PHD2's Guide Assistant is giving you a number that includes cone error.

Brian

Re: PA and PHD2

Posted: Tue Jun 05, 2018 2:53 am
by Chuck
That's a very good point about the grass....I am on grass but on a doubled over tarp but the mount was standing firm. Thanks for the info on cone error...I will check into that and how to improve upon it.

Re: PA and PHD2

Posted: Tue Jun 05, 2018 5:58 am
by turfpit
Have a look at ConeSharp https://www.sharpcap.co.uk/conesharp. This might assist with any investigations.

Dave

Re: PA and PHD2

Posted: Sun Jun 24, 2018 11:43 am
by Oshimitsu
I can't see how cone error would affect sharpcap because its using the plates to make a circle.