Cocoon Nebula

Nice work. It's not an easy target partly because it is embedded in a dark nebula which gives the impression that it is out of focus. The best images I've seen of it are long-exposure that show the "smoky" appearance of the dark nebula.

This one comes to mind but you need dark skies for this:

https://www.astrobin.com/271541/?page=5&nc=user

Kijja,

I don't want to open a hornet's nest of controversy but it may be well worth your effort to experiment with different exposures. One thing that strikes me about your Cocoon image is that it lacks brightness.

Last week I performed an experiment. I pointed my scope at PacMan and captured 6 frames at 90 seconds and 1 frame at 500 seconds. I captured calibration frames as usual and then processed in APP. The difference was pretty astounding.

Instead of arguing over theory I have discovered we need to prove it for ourselves given our equipment. Let the images speak for themselves.

The above post is true - however for people like myself in BORTLE 6+  500. 400, even 300 seconds are OUT for us. The LP takes over and we get a hot center background. 
With NB I agree. I can do 15 minute exposures and did the elephant with only 1 R  G and B 15 min each that looks quite nice. Personally with my Rasa 11 f2.2 I'm limited to 90 seconds = (

my recent image of same target. I don't use Darks or Flats either. 
Well I use to, but not since going OSC a year ago.

Kijja - looks great to me. Someone said not bright enough?  Looks fine, checks out fine. Your whitest whites are just under 255 so your lights are fine. However if you look at the levels you'll see you don't have any blacks. (the level slider is quite shy of the left side of the histogram). This makes the image appear a little milky. 
I nudged the blacks a little be closer which adds some extra snap. Not so much that we black out the dust into the background.  It's dont exceptionally well. 
your usage of correction layers was wise. 

Ron
(retired studio owner and 30 year world wide-pro photographer)
Little bump - see if you might prefer it? 

@oopfan

I would love to have much longer exposure, but my camera (QHY163) cannot do that, the stars will blow-out after 300 seconds. 

@rojoyinc

You are correct about the exposure. I wish to retain details of dark nebula as much as possible. It comes at the cost of the brightness of the red nebula. The real problem of my picture is the dynamic range, that includes dark sky quality and the quality of camera. I also love the way you retouched my image. Show what we have is better than digging out for what we don't.

Cheers,

Kijja