First Venture into Narrowband - Horsehead Nebula

[rickstanners]

Hi everyone, finally back from lurking and enjoying getting back into the hobby, having been away from it for nearly 10 years :O.

I started putting together a new setup during the lockdowns and, at Christmas, finally added some mono imaging gear and an asiair plus - this is an absolute game changer for me. I can now be up and running in 15 minutes and everything pretty much just works from the start every time - makes the hobby much more enjoyable for me when trying to shoehorn it into a busy family life!

Anyway, after the usual tour around various targets, I ended up settling down on the Horsehead for a first proper stab. I have 3 hours of 300s subs per channel (Ha, OIII, SII) in this image. Just stacked, combined, with the weighting tweaked a bit in APP (the SII seemed to be cancelling out a lot of the nebulosity in the other two channels) then a slight stretch and crop in Photoshop (processing is the next frontier I need to sit down and learn!). I also have some LRGB data too, so hoping to get some more of everything and then seeing just how much I can get out of the setup and what I can do with it.

There are a few things I still need to improve (flattener was only set roughly, may be able to tweak it better / guiding settings could be improved), but overall I was blown away with what it’s produced here in the Bristol suburbs!

The only issue I’ve noticed so far is some weird artefacts in the SII subs, most noticeable in Alnitak where it has an almost square, block-like halo around the star. Unsure what would cause that.

Anyway, thanks for reading and please let me know what I could be doing better, apart from everything!

[geeklee]

3 hours ago, rickstanners said:

Anyway, thanks for reading and please let me know what I could be doing better, apart from everything!

Nice one Rick.  The detail and nebulosity is coming through very clearly and looks great - even at 100%.  Good depth too.  Considering what you said in your post about processing - that's the only thing I would have said - some more processing would help keep stars under control (to varying degrees, depending on tools/methods), some noise reduction where applicable and any other tweaks.  Not sure if you also calibrated the subs & removed background gradients as part of the above? 

I'll mention the palette too 😅 I'm guessing this was a simple SHO one with the strong greens in Ha - it's quite something!  

3 hours ago, rickstanners said:

most noticeable in Alnitak where it has an almost square, block-like halo around the star. Unsure what would cause that.

I believe the 1600MM shows some artefacts on very bright stars.  If you search for that, you'll find some examples to check.

Edited January 23, 2023 by geeklee

[rickstanners]

Thanks Lee and yes - processing is something I've never really got into in any great depth until now. There seems to be many more good options out there than last time I looked into it (probably 10 years ago now!).

Yes, you're right on the colour palette - tbh I just picked an option that showed the most detail in the data for now just to see what was in there!

Thanks for the jog about the star artefacts, I'll have a search and see if that's what it is - thanks for your help!

[geeklee]

11 hours ago, rickstanners said:

There seems to be many more good options out there than last time I looked into it (probably 10 years ago now!).

AstroPixelProcessor (I'm assuming from APP) will give you some options in the stretch/basic processing and has some other great tools within.  The light pollution removal tool is excellent and the last few versions also have a star reduction option.  I haven't moved to the v2 beta releases yet (I typically use it for mosaics and pre-processing)

[900SL]

I recommend SiriL as an excellent stacking and processing tool. You can do background extraction frame by frame, and if you learn how to do the registration and stacking manually it opens up a lot of options. Takes a while to learn the workflow but a great piece of free software 

[assouptro]

On 24/01/2023 at 09:01, geeklee said:

AstroPixelProcessor (I'm assuming from APP) will give you some options in the stretch/basic processing and has some other great tools within.  The light pollution removal tool is excellent and the last few versions also have a star reduction option.  I haven't moved to the v2 beta releases yet (I typically use it for mosaics and pre-processing)

I too recommend astropixelprocessor There are some great tools to combine the sho in varying degrees to give less green more blue/gold as well 

Great start! Once you get the colour balance it’s going to be a fine image 😊

Bryan