ASTAP - Astrometric Stacking Program

Questions and answers about processing in StarTools and how to accomplish certain tasks.
RICH-DSO
Posts: 190
Joined: Tue Sep 04, 2018 9:02 pm

Re: ASTAP - Astrometric Stacking Program

Post by RICH-DSO »

For hotpixel, you create a hotpixel mask in StarTools and you heal/remove the hotpixels.
Clear skies
r
Carles
Posts: 191
Joined: Thu Jul 30, 2020 5:06 pm

Re: ASTAP - Astrometric Stacking Program

Post by Carles »

it shouldn't be needed to do so... since I use darks and also dithered frames.
DSS and Siril take care well of the hot pixels. for me ASTAP doesn't work well, and is very slow.

Carles.
hixx
Posts: 250
Joined: Mon Sep 02, 2019 3:36 pm

Re: ASTAP - Astrometric Stacking Program

Post by hixx »

Hi Carles,
if you cannot get rid of these artifacts in stacking, you can try to remove those in ST as a workaround.
Actually these should be a good candidate for the FLUX module's Noise setting, it is able to remove these almost completely without eating detail
I found the Flux module's algorithm very helpful for saving images with strong Shot Noise and irregular artifacts which are too strong for Denoise alone
Method see below
jochen

Removing background noise using 'Flux' module
Should exposures be short and stacks have few subs, there is always a lot of background noise that should be eliminated as much as possible while respecting the details of the objects of interest. 'Fractal Flux / Noise' preset might help a lot when adjusted suitably.
1) Launch the 'Flux' Module
2) Select the 'Noise' preset
3) Increase or decrease the 'Positive Flux' parameter. This will process the bright area. Stars get a bit rounded by decreasing this.
4) Increase or decrease the 'Negative Flux' parameter. This will process the dark area. Stars get compressed and a bit rounded by increasing this.
5) 'Filter Amount' will regulate the intensity of the filter, lower it until the brightness does not make the star core too fat.
6) 'Filter Radius' determines the radius up to which the filter will act. The larger setting, the larger the affected radius of the star will be.
7) 'Filter Fuzz' eliminates noise according to the size of the pixel that we put.
8) 'Keep' the result when you are happy with it.
Carles
Posts: 191
Joined: Thu Jul 30, 2020 5:06 pm

Re: ASTAP - Astrometric Stacking Program

Post by Carles »

hixx wrote: Fri May 21, 2021 3:41 pm Hi Carles,
if you cannot get rid of these artifacts in stacking, you can try to remove those in ST as a workaround.
Hi Jochen,

yes it can... and it does in DSS and Siril. That's precisely my point.
Now, why does it happen ? I have the reccomended settings for ASTAP and even though it doesn't remove them.

I appreaciate the method you described, but it is not necessary if i don't use ASTAP(as I don't since 1- too slow, 2- it keeps
artifacts that other stackers doesn't )

Again...if it works for others, great, but for me it doesn't. For now the one doing the best job is Siril.

Regards,

Carles.
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