alignment issue

[1jimalexander]

I've captured over 200 frames with my C11 edge HD at F6 with an ZWO 533mc. 30 sec subs. No guiding so the target moved over time but each frame was acceptable by itself. I occasionally recentered.
Calibrated with masterdark only.
Debayered.
Align: After aligning, the frames still move when viewed with Pixinsight Blink.
I assumed that, even though the original frames were moving around, the Pixinsight Star Alignment would correct for that. I guess not.
Can anyone explain might be happening here?
Thanks,
Jim

[Juno16]

I've captured over 200 frames with my C11 edge HD at F6 with an ZWO 533mc. 30 sec subs. No guiding so the target moved over time but each frame was acceptable by itself. I occasionally recentered.
Calibrated with masterdark only.
Debayered.
Align: After aligning, the frames still move when viewed with Pixinsight Blink.
I assumed that, even though the original frames were moving around, the Pixinsight Star Alignment would correct for that. I guess not.
Can anyone explain might be happening here?
Thanks,
Jim

Hi Jim,

I don’t see an attached image.

[1jimalexander]

The only thing I could show you is the integrated file that shows lots of blurry and unaligned objects.
The problem appears after alignment. The stars have not been aligned.
I'll try to think of a better way to explain this. Stay tuned.

[Juno16]

Hi Jim,

I assume that you are running the manual processes for pre-processing in PI. When you run StarAlignment, if it fails to register the images, the process console should display errors to the effect of "0 star pair matches found - need at least six matched stars.

Are you getting that error or any other error?

Have you blinked the registered files (_r postfix) and see misalignment?

Or, are you using WBPP? If you are failing registration, the reason should be in the log.

You have been using PI StarAlignment in your previous processes?

[1jimalexander]

" Unable to find an initial set of putative star pair matches"
" 5 star pair matches found - need at least six matched star"
I got the first error 2 times which agrees with the number of "failed" alignments.
The second error appeared numerous times but passed after several attempts.
I'm going to adjust the alignment parameters to pick up more stars.
However, I just did an experiment with an 11 frame sample:
1: calibrate, debayer, align, integrate
2: calibrate, align, integrate
" Without" debayering the integration was good.
"With debayering the integration was bad.
Hmmmm....

[Juno16]

You could just throw the whole thing into WBPP and see what happens.

[Juno16]

Jim, check out this link.

https://pixinsight.com/forum/index.php? ... ter.16745/

Interesting and makes sense.

Are you using Cosmetic Correction?

[1jimalexander]

This is good info. Thanks. And No I haven't been using cosmetic correction. Will give that a try.
Thanks,
Jim
Stay tuned.

[Juno16]

Great. Give it a shot. Be sure to look at the whole thread. There is other good information there too.

I had issues with hot pixels when I first started using PI and WBPP. I also have a 533 MC-P.

If you are not sure how to set up CC, check out this post that I made on the PI forum concerning CC.

https://pixinsight.com/forum/index.php? ... ost-100167

Especially check out post #11 from Adam Block. Great videos.

Good luck!

[1jimalexander]

Success! Thank you Juno 16 for your great advice.
CC corrected the alignment issue.
Adjusting the Staralign parameters for noise and sensitivity allowed 100% success with over 200 frames.

[Juno16]

Success! Thank you Juno 16 for your great advice.
CC corrected the alignment issue.
Adjusting the Staralign parameters for noise and sensitivity allowed 100% success with over 200 frames.

Super news Jim!

Yeah, it must have been trying to align on hot pixels.
I never had an issue until one dataset. I created a CC process icon and run it with WBPP every time.

Please consider sharing your image here when you are finished processing.

Take care!

[1jimalexander]

NGC2392 Clown/Eskimo Planetary Nebula

[Juno16]

Wow! Awesome!

Thank you for sharing!