NGC 6914 LRGBHa NBAccent

[Mike in Rancho]

Summer is starting to clear up.

I was inspired by Stefan's image and managed 4 hours total Ha during a couple of the full moon nights, and then 3 hours LRGB last night, most of which were before moonrise. Maybe some more would allow better stretch of the fainter reflection areas, or I could just be up against my light pollution here too.

Haven't tried too many alternatives here yet, on basically a first full go it seemed to come out pretty good. At least for the full (50 bin) file on a high dpi screen. 558b was used, and I just kept everything at defaults with no real issues, even SVD deringing. I did manually fix a few of the easiest to see ringings around some of the super tiny stars using Shrink module. But boy there are a lot of tiny stars here! I liked showing that off, so didn't use SS to push them back at all.

I think the key for this one is picking the color and strength of the NB Accent blending. I chose red in lieu of Balmer purple, but did back off the strength, and also the gamma by one click for some global darkening and increase contrast.

There's just so much to show off here. The blue reflections, all the varying star colors, and of course the nice Ha emissions and dark dust lanes. I tried to strike a balance to have the reflection and star colors easily seen, yet still get that very much red and black Cygnus-Sadr look. Not sure I fully succeeded. What do you guys think, anything to fix here?

The file is rather busy so pretty hard to smash down to 500kb. The astrobin link has the specs and also the large version in the staging area as I'm not sure this is a final yet. I think it holds up decently well on a 4K screen - if the browser or OS aren't magnifying it. Upscaled - not as clean.

NGC6914 7h LRGBHa ST9 2B 1280.jpg (490.2 KiB) Viewed 1443 times

https://astrob.in/7u5zrp/0/

[Stefan B]

Hi Mike,

great to see another take on the region

Spikes are looking razor sharp and stars are very colorful. I guess you've chosen the color constancy option? With my data the stars were a bit too colorful so I was going the artistic way to desaturate the stars a bit. But they appear perfect in your rendition!

But boy there are a lot of tiny stars here! I liked showing that off, so didn't use SS to push them back at all.

I totally agree. I usually use the Dim option in Shrink but I felt that this was killing the star field in this case. So in used Tighten. Way better here in my eyes. You have done well in highlighting the nebula without reducing the stars too much.

I think the key for this one is picking the color and strength of the NB Accent blending. I chose red in lieu of Balmer purple, but did back off the strength, and also the gamma by one click for some global darkening and increase contrast.

Agreement again I usually prefer the Balmer response simulation but in this case I also prefered the red option...did you also notice that the NBAccent effect appears much stronger with the red option than the Balmer option? In order to get the Balmer as strong as the red option you have to increase strength/gamma quite a bit. Do you have an idea why?

There's just so much to show off here. The blue reflections, all the varying star colors, and of course the nice Ha emissions and dark dust lanes. I tried to strike a balance to have the reflection and star colors easily seen, yet still get that very much red and black Cygnus-Sadr look. Not sure I fully succeeded. What do you guys think, anything to fix here?

Nothing too complain in my eyes. A great picture highlighting all the different stuff in the FOV

Regards
Stefan

[Mike in Rancho]

Hi Stefan,

Thanks. And hmm I didn't even think about altering up the style or emulation in color.

I did try another rendition attempting to stretch more and add shadow linearity, hoping to pull more of the reflection area out, but that failed. Your 7 hours broadband shows more of it, and the whole thing is very classy. Mine is a little more in-your-face.

On my most recent attempt I did create a more sedate version. A touch more Wipe to make sure I got all my gradient out of the broadband, lower dark sat and global sat to tame mostly the stars a bit, and then less strength on the NB Accent by about 20%, though still going with the red. And while the hydrogen is really the star of the show in Cygnus, I think it now bleeds a bit less and has a better balance.

NGC6914 7h LRGBHa ST9 4B 1280.jpg (533.75 KiB) Viewed 1407 times

I may stick with this and replace the abin upload.

They probably only really look different when blinked back and forth (which they do).

Totally noticed the same thing with the red versus Balmer purple and the strength requirement. I don't know if it's a perceptual illusion, something in the blending (and the new luminance and color modify options still confuse me), the underlying broadband being close to that color to start with, or that it had to somehow tame down in intensity to achieve the purple-ish color.

[Stefan B]

I don't have a good screen at hand but by blinking back and forth I can definitely see a difference. I prefer the first rendition which has a bit more punch. But may depend on the screen...

Totally noticed the same thing with the red versus Balmer purple and the strength requirement. I don't know if it's a perceptual illusion, something in the blending (and the new luminance and color modify options still confuse me), the underlying broadband being close to that color to start with, or that it had to somehow tame down in intensity to achieve the purple-ish color.

Maybe the energy of the red channel is split up to red, green and blue?

Regards
Stefan

[Mike in Rancho]

Thanks Stefan. Well, you weren't the only one who preferred version 1.

So, for a final, I went back and processed mostly mimicking the workflow of that one. My color sats I went somewhere in the middle, but closer to the levels of the first edit, and kept the same NB Accent specs. I did use my improved Shrink (no iterations) mask for the super tiny star ringing, and then I used Sharp again, though at lower strength, because otherwise the NB Accent file really only gets an OptiDev, that I am aware of, with no enhancing. I think this may have helped alleviate some of the flatness in the Ha field, and revealed some of the variability.

NGC6914 7h LRGBHa ST9 5A 1280.jpg (543.99 KiB) Viewed 1377 times

https://astrob.in/7u5zrp/0/