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Star alignement in astro landscape context

Siril Team Siril Registration H-alpha
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Raphael Lencrerot avatar
Raphael Lencrerot avatar
Hi,
I'm shooting astro landscape, I'm about to acquire an H-alpha filter 12nm Astronomik to enhance some nebulae region.
I'm looking for a tool that would align the Ha data to a reference RGB image even if the RGB data contains landscape (or foreground). I saw a tutorial on Auriga Registar that can do it, but I wonder if Siril can perform the same process? Or is it mandatory to have only stars in the reference RGB image?
I would like to avoid buying a tool specifically for this task.

Many thanks in advance,
Raphael.
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FunBin@1 avatar
FunBin@1 avatar
Hi Raphael,

doing just RGB I´m not in that Theme but the most experienced guy in Siril I know is Nico Carver. Has many YT online.

https://www.youtube.com/watch?v=rFDwGnUwOh8

If you ask him?

CS Jürgen
TJ Bagchi avatar
TJ Bagchi avatar
Hi Raphael,

As far as I know, Siril needs the stars to align. However please check with Rich at https://youtube.com/@deepspaceastro?si=shUmu5ePbYBXIUVC

He has a comprehensive Siril knowledgebase on youtube. Hope this helps. If you find an answer please do share. 

TJ
Raphael Lencrerot avatar
Raphael Lencrerot avatar
TJ Bagchi:
Hi Raphael,

As far as I know, Siril needs the stars to align. However please check with Rich at https://youtube.com/@deepspaceastro?si=shUmu5ePbYBXIUVC

He has a comprehensive Siril knowledgebase on youtube. Hope this helps. If you find an answer please do share. 

TJ

Thanks for you reply. I assume Siril needs stars to align. My question is if the RGB reference does contain landscape, is it an issue?
I saw this super tuto one by Matej explaining how he performs. But he uses a paying tool (Auriga Registar).
See here: https://youtu.be/WAXq4cbK_ZU?si=RiBjx6MPdgSniYlv

I was wondering if Siril could perform similar task. I'll ask the guys mentioned above.
Thanks
Adrian Knagg-Baugh avatar
Adrian Knagg-Baugh avatar
It won't matter if your image has some landscape in. You can make a selection and align on the stars in the selection, but regardless even with the whole image selected it will just align on the stars common to multiple images. However while that will give you sharp stars it will give you a blurry landscape as Siril can only align on one thing at once. You can address this by also stacking your images without alignment to generate a sharp landscape and blurry stars, and you will then have some work to do to blend the two stacks together to make a fully sharp final image (Siril can't do this, so you will need to take the results into gimp or krita or your preferred image editing program as layers and mask them together).
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Raphael Lencrerot avatar
Raphael Lencrerot avatar
Adrian Knagg-Baugh:
It won't matter if your image has some landscape in. You can make a selection and align on the stars in the selection, but regardless even with the whole image selected it will just align on the stars common to multiple images. However while that will give you sharp stars it will give you a blurry landscape as Siril can only align on one thing at once. You can address this by also stacking your images without alignment to generate a sharp landscape and blurry stars, and you will then have some work to do to blend the two stacks together to make a fully sharp final image (Siril can't do this, so you will need to take the results into gimp or krita or your preferred image editing program as layers and mask them together).

If I can make a selection and align the Ha only then I'm good. The Ha image that I'll use won't contain landscape (I'll delete it). I want to "prepare" the reference image from my RGB data (tracked sky merge with foreground) then have a separated Ha image aligned with the reference that I can use later in photoshop for further process.

Once I receive my Ha filter I'll make a try. Many thanks for your hint.
Karl Perera avatar
Karl Perera avatar
I use Sequator to align images with foregrounds. Again, this software is free and is great for Milky Way etc. Siril I use for deep sky objects where there is no foreground.

If you want to see how I use Sequator check this video:

https://youtu.be/w6fJd0KAdzY 

The good thing about Sequator is it easy to use and you can easily mask the foreground so the stacking freezes this part of the image and aligns the other parts of the sky and your target to create a nice image.

Try it and let's here what you think. Hope my video helps!
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