M 78

[Stefan B]

Last time I visited Orion (apart from visual) was in 2020 I guess. So it was about time and I went for M 78:

See https://www.astrobin.com/k695ak/ for technical details.

Apart from M 78 I was able to image Barnard's Loop! Well, not exactly the whole thing...

Data is pure broadband, no fancy mixing with narrowband data. Conditions were okay. Wind was strong during the first two nights with guiding about 1,1 to 1,3 arc sec. The third night was calm with 0.5'' guiding, therefore it was cut short by a cable snag...somehow after the successful flip while I was sleeping

My usual workflow with Constrast, HDR, sharp, SVD (working well!), color, shrink and SS (dimsmall + saturate) with subsequent denoise.

The image is pretty saturated (yeah, I know...), especially the hydrogen in the lower right corner but I liked the saturation of M 78 so the small loop part had to be sacrificed

Clear skies!

Stefan

[decay]

Great image, Stefan! M78 is a fantastic broadband target. Of course, you do need a dark sky and enough integration time. Both prerequisites fulfilled here Nice colours and dark nebula structures are in there, it all looks naturally – I don’t think there’s too much saturation dialed in.

Amazing to see the strong deep red of Barnard's Loop, without any NB data support.

I nearly can’t believe that you used dim small. It somehow doesn’t look that way. Anyway, well done

SV Decon often (or most times) works well for me right out of the box. I guess it depends on the actual data set, as we already discussed. Having a very close look and just to be nit picky there are some small stars embedded in the nebula that show some ringing. But of course you have to search for them:

2024-01-11 17_30_26-Window.jpg (10.82 KiB) Viewed 1640 times

And I'm not sure about the left star. Does it look unusual?

Best regards, Dietmar.

[decay]

P.S.: I revisited the full res version on AB and I'm not sure anymore. My screenshot shows strong JPEG artefacs. Not sure, if it's helpful. So just forget about it.

[Mike in Rancho]

Great shot, Stefan!

And totally cool to get that corner of the Loop in bright red, without use of NB or duo filtering.

Finding flaws really requires eyeball-to-the-monitor, and I don't see much that would require tweaking or a different workflow. Except maybe some of the mottling. That could be coming in from SS and DN?

Dietmar, you are right on both accounts, I think. There is jpg artifacting until you go to the AB version, and then hitting the full resolution button. I went one further and reopened the link in my non-scaled Firefox for 4K monitor, to keep Windows from upscaling 150%. Everything looked much better that way! Yes there are some very small rings, of the tiny star SVD variety, but so hard to see. Also a couple true halos, which struck me as a little odd with no filter.

Wow I can't believe it's been more than a year since my own M78, which I too-strongly reddened with NBA.

[fmeireso]

Beautiful Stefan.

As i allready mentioned, very nice starcolors. Startools is really good in that imho.
Finally we has some clear nights over Europe...giving us some slack to image, it has been ages. Sadly , it is allready over

[Stefan B]

Thanks for your feedback, guys. Tried to reply earlier but yesterday the forum was down I guess.

In terms of ringing that may be SVD but in some cases it was probably me being pretty heavy handed on shrink as usual. I also collected some data on M 42. There I have quite some issues regarding rings around stars. Will have to try to cure that.

Mottling...yes, I often see that in the shadows. It's always a balancing act for me to get the stretch right in order to hide the mottling. Usually I allocate less than the default 50% shadow dynamic range in OptiDev.

Finally we has some clear nights over Europe...giving us some slack to image, it has been ages. Sadly , it is allready over

We had at least 4 partly clear nights during new moon. I won't complain

Regards
Stefan