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Tracking expts with AVX and C8

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#1 bunyon

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Posted 26 April 2013 - 11:27 AM

I recently bought a new Celestron AVX to carry my old SP-C8 OTA. I had tried ASPA with the CG5 without much luck. I found I got as good a PA with my polar finder. Clearly others get good results with ASPA so I set out to figure out what I was doing wrong. I'm not sure what I was doing wrong, but I am getting good results with the AVX. Do a 2+4 align, do ASPA, bang, it's all good.

So I set about to see what the limits of the AVX are in tracking (given a full moon night with lousy seeing, what else would I do?).

The results are shown below. I got polar aligned as well as I could and attempted to confirm that by slewing in RA with the shutter open (Regulus, upper left). I then tried several different exposure lengths unguided.* 60s seemed to be fine. 150s was okay if I would be willing to lose 20-40% of my subs (see one good 150s and one bad).

I then ran the PEC routine and employed that while guiding. 150s was no sweat. 300s was fine. 600s was fine. Finally, I've posted the one 900s exposure I recorded. It was at ISO 100 with a Canon T2i, f/6.3 reducer and Hutech LPAS filter. I confirmed the identity of the asteroid by recording images over a few hours (see Solar System forum if you're interested). The guider was the Orion Finder guider.

To be honest, I'm about as happy as I can be with this outcome. I was never able to get consistently good tracking with the CG5 over 5 minutes. Here I have round stars at 15 minutes. Hopefully, it wasn't just a fluky good night.


* what is it with the desire to run unguided? AP seems pretty complicated no matter what you do, I figure you may as well make it slightly more complicated and guide, thus ensuring a more likely happy outcome. YMMV, I suppose.

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#2 bretm

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Posted 26 April 2013 - 12:00 PM

Paul:

Thanks for the report. My AVX is on the truck for delivery - I hope I get results anywhere near as good as you are...

Bret

#3 Whichwayisnorth

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Posted 27 April 2013 - 01:22 AM

I was getting similar results with mine. Other than the hand controller issue I had early on, this mount has turned out to be amazing! I could not be more happy.


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