How many attempts does it take? North American Nebula

[Thorney]

Finally manged to get out for a couple of nights last week since late Feb early March time and shoot the old faithful North American Nebula. I've done about 4 attempts at processing the data but I'm still not quite happy with it.  Every time I think, right that's it. I then save it and sit there looking at it and change my mind. So I reprocess the image and it comes out totally different.  This is probably my best  so far but I'll no doubt have another go at some point. I still feel like I am at the very basic stage of processing so in time we'll have a better outcome. 

This is about 12 hours with 30 Darks, 30 Flats & 30 Dark Flats. Shot with a Redcat, ASI2600mc, Optolong L Extreme and ASIAIR pro. Stacked in DSS and processed in Photoshop.

I've also attached the tif file incase anyone would like to have a go.

Autosave.tif

Edited August 15, 2022 by Thorney

[Clarkey]

If your anything like me you will never be completely happy. I regularly go back and reprocess images that are just 'wrong' somehow. APOCD - a new SGL acronym 😆

[Budgie1]

I had a wee play with PixInsight and came up with the image below.

Sometimes I fine the first attempt is the best, then I go back a few months later, when I've learned more processing skills and try again. Sometimes I think it's better, other times I scrap the attempt half way through.  

[Richard_]

You've done a really nice job Thorney and it looks like you had great data to work with. As @Budgie1 has shown, you do have more data hidden in the background but the trick is how to tease it out without making the image look worse (I'm really good at that part 😁). Every time I process and reprocess my images, I always learn something new even if it's something minor. 

[ollypenrice]

I think your image is well processed. Firstly nothing shouts or pokes you in the eye. The background is neutral and the black point well judged.  (This is tricky on the NAN because there are patches of dust which are much blacker than the  background sky. Stars are small and tight, noise is low and there is no visible noise reduction. There's no star colour but that's the filter's drawback. I wonder if a short unfiltered run might let you get hold of some?

Other than that the only suggestion I can make would be to try to give it a bit more punch in the form of stronger local contrasts. Since you use Photoshop (wise man!) do you have Pro Digital Astronomy Tools, formerly known as Noel's Actions? They are excellent. 'Local COntrast Enhance' would probably work on this. Normally I use it as a layer and don't select the contrast enhances stars when flattening.

Olly

[tomato]

Two very good renditions on the same data. Picking up on Olly’s comment on the dust, is the dark cross shaped region in the centre a clear ‘hole’ in the Hydrogen clouds, or is there obscuring dust there?

[Thorney]

Thank you all for the comments it’s really appreciated. 
 

10 hours ago, Budgie1 said:

I had a wee play with PixInsight and came up with the image below.

Sometimes I fine the first attempt is the best, then I go back a few months later, when I've learned more processing skills and try again. Sometimes I think it's better, other times I scrap the attempt half way through.  

Wow thank you for sharing this. Definitely a lot more details than I have and it’s good to see what can be achieved so it’s something to aim for. 
 

3 hours ago, ollypenrice said:

I think your image is well processed. Firstly nothing shouts or pokes you in the eye. The background is neutral and the black point well judged.  (This is tricky on the NAN because there are patches of dust which are much blacker than the  background sky. Stars are small and tight, noise is low and there is no visible noise reduction. There's no star colour but that's the filter's drawback. I wonder if a short unfiltered run might let you get hold of some?

Other than that the only suggestion I can make would be to try to give it a bit more punch in the form of stronger local contrasts. Since you use Photoshop (wise man!) do you have Pro Digital Astronomy Tools, formerly known as Noel's Actions? They are excellent. 'Local COntrast Enhance' would probably work on this. Normally I use it as a layer and don't select the contrast enhances stars when flattening.

Olly

Thank you for the feed back. Regarding the star, yes I’m looking at getting some unfiltered images hopefully round a new moon. I am just unsure of how to combine them, would it be a case of just stacking onto what I already have or is it best to created a layer mask and go down that round? 
 

I do have the Astronomy Tools which is heavily relied on 😆.  I will have another play though and see how I get on. I think on one of my first attempts I over done it so I’ve held back a bit in this one. 

[AstroMuni]

Beautiful image @Thorney. I wish this was taken by me.

And your raw data did give me a chance to practice my processing skills 🙂 in Siril and apply the local contrast suggested by Olly. Thank you

Edited August 16, 2022 by AstroMuni

[The Lazy Astronomer]

Based on my own experience, the answer to your question is very simple: how many attempts does it take? n+1

😜

[alacant]

Hi

Love it.

Sorry, just couldn't resist an in-your-face HOO, as there's so much detail. But with the stars:)

Cheers and clear skies.

[ollypenrice]

10 hours ago, Thorney said:

 

Thank you for the feed back. Regarding the star, yes I’m looking at getting some unfiltered images hopefully round a new moon. I am just unsure of how to combine them, would it be a case of just stacking onto what I already have or is it best to created a layer mask and go down that round? 
 

 

I haven't tried this but I think it ought to be fairly easy. I'd take the unfiltered OSC image and process it only for the stars. Don't worry about what the rest of it looks like, just get accurately colourful stars. Paste this on top of your present image, use Noel to select brighter stars, expand and feather that selection, select inverse and delete the rest. It might look OK like that but, if not, try switching the blend mode to Colour. While the stars are a top layer you can adjust saturation and, in blend mode Colour, use blur as well. In Blend mode Normal blur will blur the stars but not in blend mode colour. It has to be possible.

Olly

[ollypenrice]

12 hours ago, tomato said:

Two very good renditions on the same data. Picking up on Olly’s comment on the dust, is the dark cross shaped region in the centre a clear ‘hole’ in the Hydrogen clouds, or is there obscuring dust there?

This was E E Barnard's great question. As the stunning visual observer that he was, he didn't know the answer. When he became a pioneer in astrophotography he finally concluded that there were dark nebulae which were dark because they obscured what lay behind them. This is conclusively the modern view. I think we confirm this every time we stretch data on dark nebulae and see the background brighten as the dark nebula does not.

https://www.amazon.fr/Immortal-Fire-Within-Emerson-Barnard/dp/0521444896

Olly

Edit: The book is back in print so you don't have to pay silly prices for it.

 

Edited August 16, 2022 by ollypenrice