M 8 - Lagoon Nebula

[Stefan B]

FInally got around to process my latest data. I tried to get an image of the Lagoon nebula. It doesn't get higher than 17°here and on the first subs my neighbor's roof is featured but in the end total integration time approximated 10 hours of combined broadband and duo NB. None of the data was acquired during astro dark...since there is none at the moment

Processing was a bit of a struggle, in terms of color balancing (chromatic aberration is visible on the stars probably due to low altitude), duo NB/broadband blending (via NBAccent) and SVD. I don't get the deringing in the new alpha with the two parameters...don't know why. I used an old alpha with only one deringing parameter. Maybe I post the dataset in one of the deringing threads in order to get some advice Unfortunately I barely have time to get into this kind of details at the moment

Here's the NBAccent version:

It does look cool on some screens, much too luminous and saturated on others. I settled on a rendition which is fine on my phone and my TV...that's where I look at the images most of the time. Not a very good sign if it depends on screens but this is were I ended up after quite some processing runs.

Technical details here: https://www.astrobin.com/gfmokv/0/

Here's an H(HO)O rendition completely without broadband data:

Regards
Stefan

[decay]

Wow, Stefan! I wouldn't have thought, that this is possible from any location in Germany. 17° for your location, so less than 16 for me For sure I would see the trees of the nearby forest within my M8 ...

I don't get the deringing in the new alpha with the two parameters...don't know why. I used an old alpha with only one deringing parameter. Maybe I post the dataset in one of the deringing threads in order to get some advice

Hmmm .... I'm not sure about the current alpha, too. Maybe this again depends on special characteristics of different data sets. But I haven't tried too much until now. But I think we should give feedback to Ivo in case of any troubles. Apart from deringing current SVDecon does an awesome job for me.

Some of the stars look a bit prolonged? Do you think this is due to atmospheric refraction or do you still have problems with your new equipment? Anyway, this is a great image

Best regards, Dietmar.

[decay]

P.S.: I had a quick look in Stellarium: That's only about 14.4 degrees for me?!

[fmeireso]

It is a great image indeed.
Seems indeed some stars have a little blue ringing, CA or perhaps atmospheric diffraction of some kind.
The nebulae holds alot of detail but i would, allthough this is personal, push the color a bit. I mean getting it a bit more reddish, less magenta.

From my location in Belgium i would'nt even try it, it sits behind trees anyhow in my backyard. Luckely i could get it in the South of France last year.

[Stefan B]

Thanks for your feedback, guys!

Dietmar, I guess the oblong stars are due to atmospheric dispersion low on the horizon. Blue is up in my case... channel alignment in DSS might have fixed that but I didn't bother trying... Guiding hasn't been great either with an RMS of about 1''. Guiding on a part of the sky with higher altitude was much better with about 0.6''.

And yes, it's ridiculously low. But if you have the chance to get two hours it might already be enough for a nice image.

Freddy, I understand your preference for a more reddish color but I actually like this intense magenta in this case. It took me quite a while to get there As you said, it's a matter of taste.

Regards
Stefan

[fmeireso]

Well, my own pictures cames out pretty magenta as well...i have to admit. For some reason i did not really succeeded in turning them red. Maybe the object is just that way..

But is has alot of detail in it. i find it as rewarding as the Orion nebulae. It is just a pity , from my latitude it is just too low

[admin]

I love the visual spectrum version here!

The colors are spot-on IMO; the quintessential red/magenta is 100% expected from this H-II area, as it's a mixture of all emissions (not just pure red Ha). For example, there's Hb (blue at 1~/3rd intensity of Ha) and O-III in areas as well (teal), which will quickly yield the magenta you see here.

The varied star field temperature seals the deal - it proves a good/informative color balance.

[Stefan B]

Thanks, Ivo, greatly appreciated. Happy to hear it's a reasonable rendition!

Regards
Stefan