Uncle Rod Uncle Rod's Astroblog: http://uncle-rods.blogspot.com/
Celestron Nexstar 8SE with 6.3 focal reducer SV 90mm SVT Raptor APO Triplet Refractor Celestron AS-GT (Hypertuned) Orion SSAG/Mini-guider Canon T3i DSLR modded with Baader UV/IR filter Backyard EOS/Deep Sky Stacker/Photoshop CS5
My images: http://mtanous.wordpress.com
Quote:After reading an earlier discussion, I factory reset my ASGT and ran a two-star alignment with the dec index marks intentionally off so there is a non-zero dec index error. Dec index and cone were both reported as zero. Repeat, but this time adding one cal star. Dec index and cone both had non-zero values after adding only one calibration star. I don't think there's enough information available to solve for polar misalignment and cone or index errors after only two alignment stars. I was a bit surprised that both errors could be calculated with only one additional data point, but apparently they can.
Quote:Can someone ask the EQMOD developer if he can/wants to develop a polar alignment routine based on his N-STAR alignment?
Quote:If you want to do an ASPA after two stars use a star on the same side of the meridian as the two align stars.
Quote:Thanks Rod and George for helping and sharing your experiences!
I thought that Celestron's ASPA is more accurate because of 3 reasons:
Quote:It's such a pity EQMOD doesn't have a software routine similar to ASPA but based on its N-Star alignment considering how much powerful a PC is compared to the HC.
Quote: Quote:It's such a pity EQMOD doesn't have a software routine similar to ASPA but based on its N-Star alignment considering how much powerful a PC is compared to the HC. EQMOD utilizes a mount modeling algorithm that does not allow for easy separation of the polar axis alignment error from other pointing errors. In a nutshell, EQMOD employs a fancy geometrical interpolation method that has no understanding of underlying sources of pointing errors.
Quote: Please give us a detailed technical explanation of what you are saying.
Quote: Quote: Please give us a detailed technical explanation of what you are saying. Sorry, that's only on a need-to-know basis
Quote:Quote: Quote: Please give us a detailed technical explanation of what you are saying. Sorry, that's only on a need-to-know basis So just your usual wind and *BLEEP*, I thought so.Chris
Quote:I propose that all EQMOD users should ask kindly the EQMOD developer to create an ASPA routine based on his N-Star alignment. This routine should give better accuracy than Celestron's. I can't believe such opportunity has been missed.
What do you say guys?