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The stars are not in the stars for my stars. :-) How to fix my stars?

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#1 Juggernaut

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Posted 04 May 2025 - 01:25 PM

Hi all,

 

Had a session where for some reason my stars all have a little tail sticking out to the left. Must be a bad frame that I cannot find.

It has not been a problem on subsequent images but I would like to salvage my image if possible.

 

I thought I would be able to deconvolute the stars to fix but having no such luck.  I am using Siril and GraXpert.

1) Siril Gausian works great, but the stars look like they were pasted on the image, so no go.

2) Siril Moffat looks much more natural than Gausian but adds little pixels around the largest stars (looks like a solar system orbiting a star).

3) Graxpert deconvolution does something to the background of my star mask that makes it impossible to incorporate it back into the main image since it brings the amplification of background artifact into the image once I've stretched it in Siril.

4) Cosmic clarity adds lots of artifacts, so not helpful either.

5) I don't have PI (but maybe that is what I need?).

 

So, I guess the question is "how do I fix my stars with Siril or Graxpert in a way that will not mess up the rest of the image?"
Maybe I just have the wrong settings for the programs I am using?

Thanks for the help!

Paul


Edited by Juggernaut, 04 May 2025 - 01:35 PM.


#2 todddezcom

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Posted 04 May 2025 - 04:55 PM

You might request a free trial of PixInsight, and then a free trial of BlurXTerminator (BXT) from rc-astro.com. Depending on how bad the "tail" is, BXT might solve the problem for you. PI has a reputation for a steep learning curve, but trying out BXT would be pretty simple. Just download and install PI and BXT, then open PI, open the image file you want to work with, go to Process > All Processes > BlurXterminator. The AI should already be set to the current version. I would just start with the default values. Apply BXT to your image by dragging the little triangle in the lower left corner of the BXT dialog box onto your image, and check out the results. If you don't like how it looks, undo the process by clicking the "UnDo" arrow right below the File dropdown in the PI menubar, change the settings in the BXT dialog and reapply the process to your image. If you get something you like, save the image. If you save it as a TIFF, make sure you choose 16-bit unsigned integer for the sample format. I have to warn you though, if you try BXT, you are probably going to want to buy it.


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#3 Charlie B

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Posted 04 May 2025 - 05:31 PM

Hi all,

 

Had a session where for some reason my stars all have a little tail sticking out to the left. Must be a bad frame that I cannot find.

It has not been a problem on subsequent images but I would like to salvage my image if possible.

 

I thought I would be able to deconvolute the stars to fix but having no such luck.  I am using Siril and GraXpert.

1) Siril Gausian works great, but the stars look like they were pasted on the image, so no go.

2) Siril Moffat looks much more natural than Gausian but adds little pixels around the largest stars (looks like a solar system orbiting a star).

3) Graxpert deconvolution does something to the background of my star mask that makes it impossible to incorporate it back into the main image since it brings the amplification of background artifact into the image once I've stretched it in Siril.

4) Cosmic clarity adds lots of artifacts, so not helpful either.

5) I don't have PI (but maybe that is what I need?).

 

So, I guess the question is "how do I fix my stars with Siril or Graxpert in a way that will not mess up the rest of the image?"
Maybe I just have the wrong settings for the programs I am using?

Thanks for the help!

Paul

I presume you have Seti Astro Suite, since you mentioned cosmic clarity.  Look through your subs and delete any bad frames.  See the SAS youtube video on culling.

 

Regards,

Charlie B




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