The Elephant's Trunk Nebula

[Stefan B]

August has been very kind in terms of clear skies (although some clouds and especially rain would be fairly needed here...) and so I was able to get one more image in this month. The Elephant's Trunk in Cepheus can be imaged all night from my location and so I dedicated one night for broadband and one night for duo NB data and combined them via NBAccent. I can't stress enough how well this works with nebulae.

This region is of course known for being shown in narrowband and particularly SHO. You can find crazy rainbow palette like images on the internet. But it is also really great in a visual spectrum appearance (especially when supplemented with some subtle duo NB data).

Regards
Stefan

PS. See https://www.astrobin.com/3c2jrr/0/ for details.

[fmeireso]

I don't particulary like that object but your image looks great...

How do you use the NB function, sofar i never tried it. I have some data from the Lagoon out of France, but have issues...but maybe it would be time to try that NB function. I have about 2.5 hours of NB data and 90 minuts of OSC data...

[Stefan B]

Thanks, Freddy!

Some months ago I outlined my workflow here:

viewtopic.php?p=11380#p11380

Usually I go through the modules after Wipe and 2nd AutoDev as usual (contrast, HDR, sharp, SVD, color, shrink) and then I FIRST do NBAccent and AFTERWARDS SuperStructure. The reason is that NBAccent introduces structures I want to highlight in the SuperStructure module. This is not the recommended order in which you should do NBAccent at the very end right before denoising.

With the Elephant's trunk I took this one step (or several steps) further. I noticed that basically all detail in the image which contrast, HDR, sharp etc. work on comes from the NB data. Thus after 2nd AutoDev I went straight to color and then to NBAccent. Afterwards I worked my way through contrast, etc. So all the detail - the luminance detail coming from NB and introduced by NBAccent - was processed. This is NOT the workflow recommended by Ivo!

But I compared it to a workflow where I used NB as luminance and broadband as RGB and going through the modules as usual. Luminance wise I couldn't detect significant differences between the LRGB and the NBAccent workflow outlined above. But the colors look better with NBAccent instead of only broadband colors.

Hope this gives an idea how I've used NBAccent.

Maybe you want to share your data sets and we can try to fiddle a bit with the data

Regards
Stefan

[fmeireso]

Hi Stefan,

Here the link to the narrowband stack

https://www.dropbox.com/s/64xrwpd4asanf ... r.fit?dl=0

OSC stack :

https://www.dropbox.com/s/c73hj904q1hjp ... B.fit?dl=0

bit tilt in the aligment...unfortuantely

My best shot sofar on astrobin

https://www.astrobin.com/yq3y4b/

[Stefan B]

Hi Freddy, thanks for the datasets. I had a go at it last night but right before denoise my PC crashed Don't know if I am able to try again before the weekend...will report back as soon as I have results.
Regards
Stefan

[Mike in Rancho]

Nice Trunk, Stefan!

Generally this is not one of my favorite objects (not that I've tried it), but your framing works quite well for it here.

Freddy I did download your data as well, and...it's a tough one. Your astrobin image is quite nice already. How did you composite it together - HaRGB?

Bringing the Ha in as NB Accent, which is what I experimented with, gave me trouble. Even beyond the Ha being called ("NO FILTER" ) and the big cropping needed for the rotation. Very hard to just get some more Ha around without kind of wrecking the already-nice RGB targets, as much of the blue starts being dominated. Perhaps Ha as luminance is the better option here.

Or...could it be used for both...or is that just a scrambled mess?

[fmeireso]

Hi Mike,

Yes first of all the tilt is annoying, i just made plenty little mistakes over there in France...guess the odds were a bit against me.

I used the Ha as Luminance ( i always do) and the OSC set I put in the red/green/blue channel. Then processed as such L+synthetic L, color from OSC .

Also the problem are the starclouds, the region is just one big cloud of fine stars, which come out rather ugly colorwise, imho...

Actually which all the little mishaps i had in France, clouds, bad guiding, upcoming hazy clouds, limited time,trees and srewed up flats, i am glad it came out so well afterall...

[Stefan B]

Hi Freddy,

here's my take on your data:

Freddy M8 M20.jpg (598.21 KiB) Viewed 2341 times

I think NBAccent did add quite some faint nebulosity to the image. I went for a conventional look with a toned down HDR and the colors artistic instead of scientific.

For processing I entered color and NBAccent immediately after Wipe and then visited the other modules like contrast etc.

What are your thoughts on it?

Regards
Stefan

[fmeireso]

Hmmm, interesting.

Colors are a bit to faint for my liking but it seems indeed there is more subtle nebulosity. Colors can be easily boosted a bit up, from what i see from the jpg i downloaded. I am always a bit heavy on color..i know....Also the bok globules stand out better then in my processing.
I think i really have to have a look at that Nb accent module and learn how to use it....

edit : also the Triffid show quite more nebulosity in your processing ...

Thanks Stefan for processing, Guess the coming days i have some studying to do...

[Stefan B]

Colors are a bit to faint for my liking but it seems indeed there is more subtle nebulosity. Colors can be easily boosted a bit up, from what i see from the jpg i downloaded. I am always a bit heavy on color..i know...

Usually I am the one who's creating images with too much saturation If you go with the default in the Saturate preset in SuperStructure intense colors will hit you, don't worry I reduced the saturation value from 200% to well under 100%. But you can of course boost that a lot.

Thanks Stefan for processing, Guess the coming days i have some studying to do...

You're welcome, wishing you happy experimenting.

Regards
Stefan