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The Power of SharpCap Polar Alignment

Posted: Tue Apr 14, 2020 11:58 pm
by BlackWikkett
I have a testimonial of the unbelievable success I've had with SharpCap's Polar Alignment feature.

Normally I image from by brother's house because he has way more open sky then I have and slightly darker skies also. I've been using QHY Polemaster successfully for quite some time. Due to the pandemic causing me to shelter in place at home I'm using my 2nd mount and a 70mm Stellarvue APO. I've never been able to polar align as NCP and Polaris are obstructed by trees.
DSC00032-a.jpg
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This is my sky looking north toward the NCP. As you can see this looks to be totally obstructed. I've been using my 70mm along with an iOptron CEM25 with just a rough polar alignment that I used PHD2 to fine tune with drift alignment. This works but there's still a significant PA error and tracking suffers with excessive corrections from PHD2. As I was shutting down last night sending the mount to it's home position I thought I'd turn the exposure down to 2 sec and gain to max, 450 for the ASI183 MC. I wanted to watch the star trails as the mount slewed home. To my surprise the image on screen was showing a decent amount of stars through all the foilage! This got me thinking, If i can see stars will SC be able to plate solve for PA? Short answer absolutely! I had to play around with exposure and settled on 4 sec and gain 450 after rotating 90 degrees to continue the PA routine. In the end the polar alignment was in the green with an excellent score.

To Robin, thanks again for an amazing package you've put together!
-Chris

Re: The Power of SharpCap Polar Alignment

Posted: Wed Apr 15, 2020 1:05 pm
by nexusjeep
I second the sentiment it is an amazing feature and worth the licence fee on it's own. I polar align using my main scope and the gain almost at max and can get away with 1s exposures so almost can adjust the alignment in real time my view of the NCP is unobstructed which is a plus and usually within 30 seconds I can be within 1 to 2 seconds of perfection which is near enough.

The other night I had knocked the scope whilst setting up and not noticed so it was technically not even pointing in the right direction and Sharpcap still managed to align it. I only noticed when the plate solves kept failing and on a re home found the issue.

Cheers
Nick

Re: The Power of SharpCap Polar Alignment

Posted: Thu Apr 16, 2020 1:53 am
by BlackWikkett
SC-PA-Trees.PNG
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Captured a screen shot of completing PA through the trees!

-Chris

Re: The Power of SharpCap Polar Alignment

Posted: Thu Apr 16, 2020 10:43 pm
by nexusjeep
I take it you do not see a chainsaw in your future and a bit of severe pruning :shock:

Cheers
Nick

Re: The Power of SharpCap Polar Alignment

Posted: Fri Apr 17, 2020 9:38 pm
by admin
I do like the fact that you can actually see the tree branches in that screenshot, but the polar alignment is still working even so!

Cheers, Robin