Author Topic: Registration Fails  (Read 2983 times)

Offline Martin

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Registration Fails
« on: 2010 December 03 18:38:48 »
Hello
Really struggling to get PI to register individual frames to a large reference frame.
What I have is a 4 panel mosaic reference frame, and I am trying to register all of the RGB frames for all 4 panels against this reference frame.
PI reports registration successful, but fails to properly register the frames and there is always some residual misalignment at the edges of each frame.
The data is 3.5 arsecs per pixel and the FOV is 4 degs x 4 degs, so it is widefield data.

Even if I try to create a mosaic in PI, rather than aligning to a reference frame, I get the same misalignment at the edges.

Are there particular settings I can tweak to make this work?
thanks
Martin

Offline georg.viehoever

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Re: Registration Fails
« Reply #1 on: 2010 December 04 02:01:42 »
Hi Martin,

the problem here probably is that you are trying a wide field registration. StarAlignment is not very good with these, because it does not handle well the unavoidable distortions. If you look carefully into some of the diagnostic images that StarAlignment produces, you will see that it matches only a few stars in some region of the image, and it does not match stars in other parts of the image.

In my experiments, e.g. http://pixinsight.com/forum/index.php?topic=2068.0,  always ended up manually aligning the frames to some map using DynamicAlignment.

Georg
Georg (6 inch Newton, unmodified Canon EOS40D+80D, unguided EQ5 mount)

Offline Martin

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Re: Registration Fails
« Reply #2 on: 2010 December 06 16:34:55 »
Thanks for the post and the information George.

Martin