Shot these nearly a year ago, and didn't get around to processing it until now. I really like how the Ha addition helped with these galaxies. Captured over 4 nights in January/February, 2022 from a Bortle 6 zone
**Places where I host my other images:**
[Instagram](https://www.instagram.com/leftysastrophotography/) | [Flickr](https://www.flickr.com/people/leftysastrophotography/)
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**[Equipment:](https://i.imgur.com/ejpKkwU.jpg)**
* TPO 6" F/4 Imaging Newtonian
* Orion Sirius EQ-G
* ZWO ASI1600MM-Pro
* Skywatcher Quattro Coma Corrector
* ZWO EFW 8x1.25"/31mm
* Astronomik LRGB+CLS Filters- 31mm
* Astrodon 31mm Ha 5nm, Oiii 3nm, Sii 5nm
* Agena 50mm Deluxe Straight-Through Guide Scope
* ZWO ASI-290mc for guiding
* Moonlite Autofocuser
**Acquisition:** 11 hours 29 minutes (Camera at Unity Gain, -20°C)
* L- 164x90"
* R- 55x90"
* G- 54x90"
* B- 53x90"
* Ha - 40x300"
* Darks- 30
* Flats- 30 per filter
**Capture Software:**
* Captured using [N.I.N.A.](https://nighttime-imaging.eu) and PHD2 for guiding and dithering.
**PixInsight Processing:**
* BatchPreProcessing
* SubframeSelector
* StarAlignment
* [Blink](https://youtu.be/sJeuWZNWImE?t=40)
* ImageIntegration
* DrizzleIntegration (2x, Var β=1.5)
**Linear:**
* DynamicCrop
* DynamicBackgroundExtraction
* EZ Decon (lum only)
* NoiseXTerminator (lum only)
* ArcsinhStrecth + HistogramTransformation to bring nonlinear
**RGB:**
* Channelcombination to combine monochrome images into RGB image
* PhotometricColorCalibration
* SCNR green
* HSV Repair
**Adding Ha:**
> I followed this tutorial which had great results on some [prior](https://www.reddit.com/r/astrophotography/comments/q8ogec/m33_the_triangulum_galaxy_in_halrgb/) HaLRGB [galaxy pics](https://www.reddit.com/r/astrophotography/comments/ml2os3/m51_the_whirlpool_galaxy_in_halrgb/):
> http://www.arciereceleste.it/tutorial-pixinsight/cat-tutorial-eng/85-enhance-galaxy-ha-eng
* PixelMath to make Clean Ha. This effectively [isolates just the Ha regions](https://i.imgur.com/Aob3UEO.png) from the red continuum spectrum
> Ha-Q * (Red-med (Red))
> Q=0.16
* PixelMath to combine Clean Ha
* PixelMath to add Ha to RGB image ($T)
> R= $T+B*(Ha_Clean - med(Ha_Clean))
> G= $T
> B= $T+B\*0.2*(Ha_Clean - med(Ha_Clean))
> B=1
**HaRGB:**
* Slight SCNR
* ArcsinhStretch + HistogramTransformations to stretch nonlinear
**Nonlinear:**
* LRGBCombination with stretched luminance
* Shitloads of CurveTransformations to adjust lightness, saturation, contrast, hues, etc.
* color saturation to slightly desaturate the Ha regions
* More curves/color saturation adjustments
* Extract L --> LRGBCombination for background chrominance noise reduction
* even more curves
* NoiseXTerminator
* LocalHistogramEqualization
> Two rounds of this. one at size 16 for the finer 'feathery' details and one at size 200 for large scale structures
* EZ Star Reduction
* noise generator to add noise back into star reduced areas
* Invert > SCNR > invert to remove some magentas from the galaxy
* More curves
* MLT for large scale chrominance noise reduction
* guess what even more curves
* Resample to 70%
* Annotation
lefty7283
