So this is [my third time shooting NGC 7380](https://i.imgur.com/xCdlJTA.png) (previous pics were from 2018 and 2020). This time around I decided to go with a different false-color palette (exact details below) compared to my prior true color and Hubble palette pics. Captured over 4 nights in Nov/Dec, 2023 from a Bortle 9 zone.
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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-120mc for guiding
* Moonlite Autofocuser
**Acquisition:** 12 hours 48minutes (Camera at unity gain, -15°C)
* Ha - 33x360"
* Oiii - 52x360"
* Sii - 43x360"
* 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:**
**Preprocessing**
* BatchPreProcessing
* StarAlignment
* [Blink](https://youtu.be/sJeuWZNWImE?t=40)
* ImageIntegration per channel per panel
* DrizzleIntegration (2x, Var β=1.5) per panel per channel
* StarAlignment in mosaic mode to align the two panels, then GradientMergeMosaic to combine them
**Linear:**
* DynamicBackground Extraction
> duplicated each image and removed stars via StarXterminator. Ran DBE with a shitload of points to generate background model. model subtracted from original pic using the following PixelMath (math courtesy of /u/jimmythechicken1)
> $T * med(model) / model
* BlurXTerminator
* NoiseXterminator
* Duplicated images, to be used later for stars only processing
* STF applied via HistogramTransformation to bring nonlinear
**Stars processing:**
* Extracted stars-only pic using StarXterminator
* Pixelmath to make color SHO --> RGB image
* SpectroPhotometricColorCalibration (narrowband working mode)
* ArcsinhStretch + HT to bring nonlinear
* SCNR > invert > SCNR >invert to remove greens and magentas from stars
* Stars only pic saved for later addition to starless pic
**Nonlinear:**
* StarX to remove all stars
* PixelMath to create color image in OSH --> RGB palette
* PixelMath to make a second image using Jimmy's Royal Palette:
> R = 0.3\*Oiii+0.7\*(Oiii\^~(0.7\*Ha+0.3\*Sii))\^1.2
> G = ((Oiii\*Ha)\^~(Oiii\*Ha))\*Ha + ~((Oiii\*Ha)\^~(Oiii\*Ha))\*Sii
> B = 0.9\*Sii+Ha-Oiii
* PixelMath to blend OSH and Jimmy pics together 50:50
* LRGBCombination using stretched Ha as luminance
* shitloads of CurveTransformations to adjust hue, lightness, saturation, etc. (some with lum masks)
* another round of NoiseXTerminator
* Extract L --> LRGBCombination for chrominance noise reduction
* LocalHistogramEqualization
* More curves
* MultiscaleLinearTransform
* Relinearized narrowband and stars images to add in the stars only image
> "unstretched" both images with histogramtransformation midtones set to 0.9999
> pixelmath to just add those two images together
> histogramtransformation to un-relinearize them by setting midtones to 0.0001
* Even more curves
* Resample to 60%
* annotation
lefty7283
