More RASA8: Propeller Nebula (DWB 111, 119) & Co in Cygnus

[gorann]

This is the first nebulosity that I have aimed at with my new RASA8 and ASI2600MC. Kind of hard to process due to the rich star field. I should get Starnet++ but my OS on the Mac is too old for it. I also shot it before I organized the camera cables in a circle so stars are a bit odd and spiky, but not too bad. I may collect som Ha for it next time it clears.

The propeller nebula (also known as Simeis 57) is up in the left corner and kind of obvious. I like the dark nebulosity and globules apparently laying above the Ha structures. I think the dark area down to the right is a big chunk of dark nebulosity and not background sky.

125 x 90 seconds at gain 100 (offset 30). NEQ6 mount. Stacked in PI and mainly processed in PS.

Edited August 20, 2020 by gorann

[Datalord]

Hmm, this one seems a bit saturated to me. How was the processing of this one?

[MarkAR]

A lot of good nebulosity there, does look a bit saturated to me.

8 hours ago, gorann said:

I should get Starnet++ but my OS on the Mac is too old for it

Even too old to add it to PI as a plug in script? (Might be a different version for this)

[ollypenrice]

I agree with the others. I think the intensity of the reds rather flattens them. But the system certainly works.

Olly

[gorann]

9 hours ago, Datalord said:

Hmm, this one seems a bit saturated to me. How was the processing of this one?

 

8 hours ago, MarkAR said:

A lot of good nebulosity there, does look a bit saturated to me.

Even too old to add it to PI as a plug in script? (Might be a different version for this)

 

4 minutes ago, ollypenrice said:

I agree with the others. I think the intensity of the reds rather flattens them. But the system certainly works.

Olly

Yes, you are all right. It is over saturated and I was not that pleased myself but there is just such a dominance of the red signal (even if it is only a quater of the pixels on the chip). However, I think I now came up with an easy way to fix it using Selective Color in PS and turning up the blue signal in the red. It also brought out details a bit better. So what about this?

[ollypenrice]

Just now, gorann said:

 

 

Yes, you are all right. It is over saturated and I was not that pleased myself but there is just such a dominance of the red signal (even if it is only a quater of the pixels on the chip). However, I think I now came up with an easy way to fix it using Selective Color in PS and turning up the blue signal in the red. It also brought out details a bit better. So what about this?

That was a good move but I'd still be inclined to lower the saturation, maybe just in the reds. In this red-dominated kind of target I think it also helps to increase the colour intensity in the blue stars. It provides a contrast.

Olly

[gorann]

26 minutes ago, ollypenrice said:

That was a good move but I'd still be inclined to lower the saturation, maybe just in the reds. In this red-dominated kind of target I think it also helps to increase the colour intensity in the blue stars. It provides a contrast.

Olly

Thanks for the suggestions Olly. Did another red adjustment and saturated the blue stars - it did help. I must have stared too long at this data to see clear!

[tooth_dr]

That’s a beautiful image, the final version is great.  Should add this to my list of targets 

[gorann]

49 minutes ago, tooth_dr said:

That’s a beautiful image, the final version is great.  Should add this to my list of targets 

Thanks Adam, much appreciated!

[Datalord]

7 hours ago, gorann said:

Thanks for the suggestions Olly. Did another red adjustment and saturated the blue stars - it did help. I must have stared too long at this data to see clear!

It's a vast improvement!

I think perhaps I would try extracting L on this one, sharpen and contrast it hard and blend that back in. There's something too flat in all the redness that just doesn't sit well with me.

Full disclosure, this is an NaN I did some years back and I had the same problem and I cringe every time I look at it. Perhaps it's just me. It's a refractor image, but with a one-shot color camera.

[gorann]

I could try to do a separate lum processing - cloudy here so nothing better to do AP wise.

[astro mick]

What ever Goran,its still a lovely image.

Mick.

[wimvb]

Göran ( @gorann ) was so kind to share the unprocessed image with me. So here's my version, processed in PI, as usual.

(click on the image to get to the full size version)

The process in a nutshell:

• DBE, background neutralisation, colour calibration
• Arcsinh stretch in two steps, followed by curves transformation (contrast and saturation)
• Removed stars with StarNet++
• Boosted contrast a bit more in the starless image
• I then used masked stretch on a copy of the linear image
• Inserted the stars from the masked stretched copy into the starless image, using PixelMath and a star mask.
• Noise reduction to get rid of the slight mottle in the background
• cropped and flipped the image to get this orientation.

[gorann]

Wim, you got a really nice colour and sky mix there, better than me. I like it a lot. I think I got a bit more detail out of the data so a 50:50 mix would maybe nail it.

[gorann]

So I could not stop myself from making a simple 50:50 mix and it looks quite good. Obviously one could be more selective and mix just the best parts/regions using layers.