Orion constellation taken @ 50mm f/3.2

Hello everyone.
Currently in a general lockdown I try to think about something else.
Then, I shot deep sky. For this image, I used a Canon 100D where the original filter has been removed and replaced by another one with higher cutoff and dedicated to astronomy. I’ve also added a narrowband filter, called Halpha.
This is why my result is monochrome.
But thanks to this filter, the contrast is really enhanced for all hydrogen clouds that emit light in the same wavelength that the filter.

All the process has been done with the current dev branch of Siril.
This is an addition of 48 images of 120s.



That is super cool! Can you shoot this from your back yard?

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Yes. I can’t go out … So I’ve no choice :).
But Halpha filter is pretty cool as it stops light pollution. Moreover, I live in the countryside.

Just did a pseudo-color with some curves and frequency separation magic.
Edit, added redshift and blueshift to the stars.


Just curious, I know near nothing about astro, but don’t you get star trailing at 120s?

And for the “48”, did you all the dark, bias etc?

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Hello. That is fun, thanks :).
However I should try to add true RGB channels (with no filters). The problem is that the Moon is here now. In consequence there are a lot of light pollution.

No I use a small mount that compensate the earth rotation

Yes of course :slight_smile:

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Just curios as this is an unusual notation for photography: Does f3/2 denote an aperture ration of 1:1.5 (or f/1.5 opening)?

Oh gosh. This is a typo!!!
This is f/3.2.

I’ve fixed it.

I love these Ha shots!
Just out of curiosity, which bandwidth for the filter? The really thin like 6nm or a broader 12nm? Contemplating getting one myself for nights when the moon is out. Just wondering if focusing isn’t just too difficult with the 6nm.
Anyway, thanks for sharing!

This is the 6nm :).
Yes sometimes it is not easy for the focus. But if you choose a very bright star, it is ok.

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Wonderful shot!

Thank you.

This night I hope I will add rgb layers :).

This will be superb!. Since the quarantine started in Spain I’ve got zero clear nights :(. Good luck this night :slight_smile:


Evening everyone.
So I tried to add rgb layers tonight. Sadly, my mount battery was low, I did not know that. So I only shot 42 images of 60sec. That is not a lot.

So the result is here, a mix of Ha and rgb:


I’ve added RGB frames and Ha too.

Now, I have a result I really love with an total integration of 4.2 hours. We can see much more details.

  • 89x60" ISO800 for RGB
  • 83x120" ISO1600 for Ha


Stunning image. Thank you for sharing it

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