Horsehead/Flame. (HaL)(RHa)GB + moon experiment (Pam Whitfield)

Horsehead/Flame. (HaL)(RHa)GB + moon experiment

Revision title: reprocessed data from scratch with PI/NSG and x2 drizzle (HaRGB)

Of course the best conditions in the UK for ages coincided with a bright moon.....

It's about 6 years since I had a go at the Horsehead so time to see if I've learned anything useful!

This was a bit of an experiment over 4 consecutive nights due to weather/field-of-view restrictions blending Ha into both luminance and red channels to try and reduce the interference from the moon in a largely broadband image. It's the first time I've used 1x1 binning for RGB in anger for a long exposure image. The wildly different seeing over the nights has left a slight fringing but I'm happy enough with this image for the time being - 4 nights imaging in a row = sleep deprivation!

The G and B channels in particular were very washed out with light pollution (can't use the IDAS LPS filter at the same time as the Ha) and the moon but the Ha/L luminance layer dragged it back .

There's enough data here that I settled for a more subtle processing rather than the sledgehammer approach :-)

BTW I think the faint dark line towards the upper left is a shadow from my washing line in the Ha - mundane reality strikes again!

Original
Final
B

B

Title: reprocessed data from scratch with PI/NSG and x2 drizzle (HaRGB)

Description: This is one I can say that I'm close to 100% happy with! I'm particularly pleased with the appearance and contrast of the dust below the Ha emission region and the reflection nebulae. Previous versions clipped the blacks and lost the subtle details. I'm pretty happy with the overall colour balance and noise level too. Alnitak came out as pure white in the processing (300s RGB subs will do that!) so I changed its colour balance slightly to give it a hint of blue. I dropped the L subs completely as they didn't add anything useful and injected noise (probably read-noise being a CCD) as shorter 180s subs.

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Status	Advanced success
Started	...
Astrometry.net job	6565137
PixInsight job	OWB6D1FNSDS5XR511ROLEBRO1QXFN7YP
PixInsight queue size	n/a
PixInsight stage	TASK_LOG

RA (center)	05h41m39s.28
RA (top/left)	05h39m29s.51
RA (top/right)	05h39m32s.37
RA (bottom/right)	05h43m49s.16
RA (bottom/left)	05h43m46s.70

Dec (center)	-02°11′23″.5
Dec (top/left)	-01°28′24″.5
Dec (top/right)	-02°54′57″.7
Dec (bottom/right)	-02°54′22″.4
Dec (bottom/left)	-01°27′49″.7

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