Fishhead Nebula, NGC 896: L(Ha)SHO narrow band composite, Foraxx Palette

[windjammer]

Hi
Here is NGC 896, IC 1795, LBN 645, the Fishhead Nebula in L(Ha)SHO narrow band.  Image and annotated vs. The image is rendered with the Foraxx Palette Utility script in PixInsight. Rig and processing details at the end.

Data taken in Astronomik narrowband filters: Ha (656nm), Sii (672nm) and Oiii (501nm). Total exposure time 15 hrs.

Ha 1x1 bin - 22x 600s = 3.7hrs, 03-04 September, seeing 2.6", scope West side, prime focus
Sii 1x1 bin - 33x 600s = 5.5hrs, 04-05 September, seeing 1.8", scope West side, prime focus
Oiii 1x1 bin - 35x 600s = 5.8 hrs, 05-06 September, seeing 1.2", scope West side, prime focus

Simon

and annotated:

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Master Lights:
FWHM (pxl)    pre BXT        post BXT
Ha                    2.440         1.476
Sii                     2.942         1.666
Oiii                   3.163          2.524

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Plate solver:
Resolution ............... 1.247 arcsec/px
Focal distance ........... 750.71 mm
Pixel size ............... 4.54 um
Field of view ............ 56' 1.8" x 43' 58.3"
Image center ............. RA:  2 28 13.183  Dec: +62 01 33.70
Image bounds:
   top-left .............. RA:  2 24 25.590  Dec: +62 25 19.95
   top-right ............. RA:  2 32 27.835  Dec: +62 21 12.52
   bottom-left ........... RA:  2 24 04.018  Dec: +61 41 26.22
   bottom-right .......... RA:  2 31 54.880  Dec: +61 37 24.65
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Rig:
Imaging scope: SW Startravel 150mm F5 Refractor, Baader Diamond Track, (2.5x Celestron Luminos 2inch imaging barlow), Atik 460EX mono

Guide scope: SW Evostar 90mm F10, with guiding XY stage, ZWO 120MM camera

Guiding: 2 stage PHD: high frequency guide scope (mount tracking) and low frequency OAG image train guiding (guidescope flex)

Mount: Home made German Equatorial pillow block mount, permanently rooftop mounted.  Spring loaded DEC axis gearing.

Other gadgets: ST4 based anti vibration shutter, ST4 based PEC
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Processing Lights:
PixInsight: Lights, Darks, Flats, Biases: master dark/dark library-> masterbias-> superbias-> calibrated flats-> master flat-> calibrated lights-> cosmetic correction-> aligned lights-> master light-> BXT

PixInsight: Master BXT lights-> crop-> linfit-> final master lights

PixInsight: final master lights->StarNet2 starless-> LRGB Channel Combination (Ha, SHO)-> export xisf starless master.

GradXpert Gradient removal:->import starless xisf-> GXPT(20pc,3sg)-> export xisf, fits 

Affinity Photo 32 bit image processing:-> import LSHO gxpt starless fits-> accept default stretch-> curves-> lvl(master)-> Topaz Denoise(LL, 22, 31)-> Tpzdn(ST,15,13)-> export tiff 16 bit

PixInsight: import tiff16-> channel separation-> Foraxx Palette Utility Script-> export Foraxx tiff 16

Affinity Photo final tart ups:-> import Foraxx tiff 16-> cvs-> scol (50%blend)-> 2x clarity, B&C tweaks->Tpzdn(LL,3,0)-> paste in star mask layer, blend mode 'screen', B&C, White Balance adjust.

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Processing Star Mask:
PixInsight: final master lights-> RGB Channel Combination (SHO)-> export xisf

GradXpert Gradient removal:->import xisf-> GXPT(20pc,3sg)-> export xisf

PixInsight: import SHO gxpt master-> StarNet2 star mask-> SCNR(Mg, 0.57)-> export fits starmask

Affinity Photo 32 bit image processing:-> import SHO gxpt starmask fits-> accept default stretch-> vibrance-> Sii master light star mask overlay (B&C adj, blend mode 'luminosity')-> paste Star Mask layer on top of starless final (blend mode 'screen'). 

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[simmo39]

V nice, never seen this target quite so close before.

[windjammer]

Its a good looking fish, splashing its way through the Milky Way spinning off stars and turbulence!  I love the catfish type barbels around the 'mouth' region.

[WolfieGlos]

Nice image! Like simmo, I don't think I've seen it this close up before either.