like half the data is missing from lightbucket ¯\_(ツ)_/¯
The spaghetti nebula (Sh2-240) is a supernova remnant in the constellation Taurus. This nebula is [fairly large in terms of angular size](https://i.imgur.com/NwRs5Zz.jpg) in the sky, coming in at around 4 degrees long at its widest point. I opted to only do a 2 panel mosaic of it because larger mosaics are a pain to process right. I decided to keep this one dim-looking overall to better reflect how faint this nebula actually is. For those curious [this inverted Ha pic](https://i.imgur.com/89eBgJk.jpg) (downsampled) helps show the fainter parts of the structure. Captured over 6 nights from November 12th through December 12, 2021 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/6T8QNsv.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:** 28 hours 0 minutes (Camera at Unity Gain, -15°C)
Panel 1:
* Ha- 58x600"
* Oiii- 28x600"
Panel 2:
* Ha- 57x600"
* Oiii- 25x600"
* 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)
* several rounds of DynamicBackgroundExtraction to remove as many gradients as possible before combining the mosaic
**Making the mosaic:**
* StarAlign left Ha panel to right (Register/union mosaic mode) to make master mosaic
* StarAlign all panels from all filters to master mosaic (register/match mode)
* GradientMergeMosaic to combine aligned panels into single mosaic image per filter
**Linear:**
* DynamicCrop
* AutomaticBackgroundExtraction
* EZ Denoise per channel
* MaskedStretch+HistogramTransformation to stretch each channel nonlinear
* Slight curve adjustment on the Oiii channel to better match the background brightness of the Ha
**Combining Channels:**
* Monochrome Ha and Oiii images combined into a color image using [ForaxX's HOO palette](https://thecoldestnights.com/2020/06/pixinsight-dynamic-narrowband-combinations-with-pixelmath):
> R= Ha
> G= ((Oiii\*Ha)\^~(Oiii\*Ha))\*Ha + ~((Oiii\*Ha)\^~(Oiii\*Ha))\*Oiii
> B= Oiii
**Nonlinear:**
* Extract Synthetic Luminance
* LRGBCombination using synthetic luminance for chrominance noise reduction
* Shitloads of CurveTransformations to adjust lightness, saturation, contrast, hues, etc.
* MLT noise reduction
* HistogramTransformation
* EZ Star reduction
* NoiseGenerator to add noise back into star reduced areas
* LocalHistogramEqualization
* more curves
* SCNR
* MMT do de-splotch the background
* even more curves
* IntegerResample to 50%
* Annotation
lefty7283
