NGC 6357 Lobster Nebula in SHO and HOO

[Startrek]

This is only my second time capturing NGC 6357 commonly referred to the Lobster Nebula ( aka War and Peace Nebula ) First time was over 2 years ago using a OSC and Dualband which resulted in a poor image due to insufficient data and poor conditions.

This time using a bigger scope, a 2600MM with 3nm filters and significantly more data ……,
Captured over 2 nights ( 11 hours integration)
Waxing Moon 60% to 70%
Seeing conditions average
Bortle 8 City suburban skies
8”f5 Klaus Helmerich Carbon fibre Newtonian Reflector
Skywatcher EQ6-R pro mount
ZWO 2600MM cooled to -10C , Gain 100
ZWO 7x2” EFW
ZWO EAF
Orion 60mm guide scope with helical focuser
ZWO 120MM guide scope
PHD2 Multistar guiding ( total error avg 0.50 to 0.60 arc sec )
Antlia 3nm Filters
Ha 60 x 5min dithered subs
Oiii 39 x 5min dithered subs
Sii 37 x 5min dithered subs
Darks frames from Library
Flats Ha , Oiii and Sii
Flat Darks Ha, Oiii and Sii
Analysed , Calibrated, Stacked and Aligned in ASTAP
Processed in Startools V1.8 via Compose
Colour HST / SHO preset with saturation and colour bias adjustments
Also processed a HOO version as well.

Although initial stretch was still quite noisy , the final image turned out much better than my previous attempt

In hindsight framing could have been better , the object should have lowered in the frame to expose more of the upper nebulosity arm or claw !!

Links to Astrobin below for full resolution…….,

https://www.astrobin.com/3y67e2/
https://www.astrobin.com/km14mc/
https://www.astrobin.com/5uyeqh/
https://www.astrobin.com/56ddk1/

Thanks for looking
Comments welcome
Martin

[Startrek]

2 more versions

[jlh]

Hi Martin,

Nice images. Did you use any particular module settings to bring out the OIII in your HOO image?

Jeff

[Startrek]

Hi Jeff,
I just used the Bi Color preset in the Color Module which takes you to the Duoband HOO setting in the Matrix and then backed off the G bias slider whilst adjusting the R slider a bit.Also bumped up the saturation as well.
Surprised me how well it came out

Forgot to mention I used L + Synthetic L from RGB , RGB for luminance color in Compose ( not Bi Color )

Martin