Prawn Nebula in SHO

[AnakChan (Sean)]

The Prawn Nebula (IC 4628) in SHO taken on 20th May 2021 under suburban Perth Bortle5/6 skies.

Takahashi µ250CRS
ZWO ASI6200MM
Antlia Pro 3nm Narrowband filters
-10C 0 Gain 50 Offset Bin 1x1

Ha: 22x 5 min
Oiii: 18x 5 min
Sii: 17x 10 min
Total: 6 hrs 10 min

[Nikolas (Nik)]

so beautifully smooth

[Andy01 (Andy)]

Nice image Sean, probably presents better orientated 90 degrees anti-clockwise though!
Well done

[multiweb (Marc)]

That's a very detailed shot Sean. The only odd thing to my eye is the very sharp cut off in the red channel between the Oiii and Sii/Ha ridge. Doesn't look like it's a channel clipping but maybe due for a repro.

[AnakChan (Sean)]

Nik/Andy/Marc, cheers! Processing took about 2 days esp with Starnet being slow on the Mac (no Nvidia).

I’m out from home at the moment but I’ll try rotating. Didn’t know that’s the normal orientation.

Marc, you’re right it’s post proc. Good catch! I made a quick overview of the individual channels and the cutoff isn’t as sharp. I probably accidentally introduced it during the CurvesTransformation stage during the non-linear processing.

[Geoff45 (Geoff)]

Nice pic Sean
I think Andy is right about rotating it. It springs to life when you do this. BTW "normal" isn't necessarily "best". I often fiddle around with rotations and crops to get what (to my eye) looks best and I don't worry if it's not "north up, west right".

[AnakChan (Sean)]

Cheers chaps. I rotated 90 CCW. This is what you mean?

[Andy01 (Andy)]

Bazinga!

[AnakChan (Sean)]

Tweaked to address Marc's comment too

[TrevorW]

Very nice, a lot smoother as per Marcs comments but as I don't shoot in mono/multichannel I could not suggest which channel may need tweaking to give a more natural result

[AnakChan (Sean)]

No worries Trevor. Marc helped to point to me specifically where. I was using Steven Miller's processing workflow (Recommend checking out!! It works out well if applied correctly. You can find it here: https://youtu.be/43ZRVvtK5GI?t=1766).

So using the ColorMask, I generated the Cyan, Green and Yellow mask. You can see that in the Cyan and Yellow mask, is where that hard transition was occurring in my previous pix.

So Marc's comment made me revisit the masks to see if it needed more blurring (but that affected the rest of the mask too, not just that portion of transition). But then I noticed the Green mask provides the smoother transition. So in the revised one I boosted with the Green mask to help the smooth out the transition. But the result is a less blue, and maybe a slight more tinge of green.

However I think it worked out reasonably well. Will need to see if there's any hues I need to tweak further.

[Robert_T]

great prawn. love the colour and highlight detail. I quote like the first orientation myself :-)