Author Topic: Another Moon alla Pixinsight  (Read 2538 times)

Offline Ignacio

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Another Moon alla Pixinsight
« on: 2013 August 22 07:03:21 »
This is my second try processing moon images with PI. I used some old data in this one. Essentially the same workflow as before, but with only 40 stills this time (vs 100 in previous image), and with no color enhancement. All 40 of them aligned properly with SA.

I noticed that one of the hard parts to align is the limb, and that to get the best results one needs to lower the Maximum Distortion parameter in Star Detection, in this case to 0.1. This pushes up the number of alignment "points" on the surface. I typically got about 14 iterations in distortion correction, converging every time.

Straightforward and consistent results!

http://www.pampaskies.com/gallery3/var/fulres/halfmoon_pi_hires.JPG

best
Ignacio

« Last Edit: 2013 August 22 08:37:27 by Ignacio »

Offline slang

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Re: Another Moon alla Pixinsight
« Reply #1 on: 2013 October 22 02:30:48 »
Wow, again.

Thanx for the descriptions of your workflow - I'm currently processing some moon shots from the other night - hope to have some decent results now that I can get PI to register/stack and align based on your work.

Cheers -
--
Mount: Orion Atlas 10 eq-g, GSO RC8, Astrophysics CCDT67
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Offline Jules

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Re: Another Moon alla Pixinsight
« Reply #2 on: 2013 October 22 04:17:47 »
Ignacio

Thats a gorgeous image, crisp and sharp!

Regards

Julian

Offline Ignacio

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Re: Another Moon alla Pixinsight
« Reply #3 on: 2013 October 22 16:54:21 »
Slang and Julian, thank you for your comments, and for waking-up this long forgotten post!

Ignacio

Offline pfile

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Re: Another Moon alla Pixinsight
« Reply #4 on: 2013 October 22 18:05:17 »
i tried this and failed; i can see plenty of detected "stars" that should overlap but SA has a hard time computing the matches, even with previews. in fact it seemed to work a little better without previews.

also made the mistake of trying to use the 2d- surface spline registration model... got some really weird distortions!

anyway a printout of the StarAlignment settings you are using would be helpful...

rob

Offline Ignacio

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Re: Another Moon alla Pixinsight
« Reply #5 on: 2013 October 23 05:02:02 »
i tried this and failed; i can see plenty of detected "stars" that should overlap but SA has a hard time computing the matches, even with previews. in fact it seemed to work a little better without previews.

also made the mistake of trying to use the 2d- surface spline registration model... got some really weird distortions!

anyway a printout of the StarAlignment settings you are using would be helpful...

rob

Hi Rob,

Definitely use Projective Transformation and not 2D Splines. The only thing that I change from defaults are:

1. Check Distortion correction
2. Increase iterations if necessary
3. Detection scales: 8 (default is 5)
4. Maximum distortion: 0.1 (default is 0.5)

That's it. Give it a try.
best
Ignacio