PixInsight Forum (historical)

PixInsight => General => Topic started by: sandconp on 2019 December 01 19:04:36

Title: Elongated Stars
Post by: sandconp on 2019 December 01 19:04:36

I processed my Rosette image in PI and I noticed that my stars were all going the same direction kind of an oblong look.  I realize that I will need to figure out in the first place while this occurred with my guiding or optics but I was wondering if there was a way to fix this using PixInisght?

I have read a few posts on the best way to do this with PI using Deconvolution and PSF or Morphilogical Transformation.  Is there a preferred way to do this in PI?

I am posting my image below to show the problem:

https://www.dropbox.com/s/9v3fadhijwxt9k3/NGC22392.jpg?dl=0

Title: Re: Elongated Stars
Post by: hoxca on 2019 December 03 15:11:07

A morphological will not help you much.

If the trail is uniform on the whole image, i think a deconvolution can help you more.
As Carlos Milovic said in another thread: use the DynamicPSF process to create a synthetic PSF that matches the trailing of your stars, and then load that PSF as an external image in the deconvolution process window.

Title: Re: Elongated Stars
Post by: sandconp on 2019 December 03 15:35:08

I did try that but did not have much luck.  I watched this good video on it.  The trail is uniform across the image.  I created a luminance copy and worked off of that image.

https://youtu.be/ZLef9GlHLrs

I may try it again since I might up messed it up.

Title: Re: Elongated Stars
Post by: Geoff on 2019 December 03 16:05:45

Just remember that when you do the deconvolution you will only need 3-5 iterations to correct the stars