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lefty7283

Sh2 115

  • 5 sessions
  • 149 images
  • 14.9 hours

Details

Little bit late to the September Object Of The Month Contest, on this one; definitely check out [the other great pics submitted](https://www.reddit.com/r/astrophotography/comments/pfnxev/ootm_object_of_the_month_september_2021/)! For those curious, the circle near the top middle is Abell 71/Sh2-116, once thought to be a planetary nebula, but now we think it's just a HII region in the foreground of the rest of the structures in the image. Also made a [starless version](https://i.imgur.com/FJpmsQ8.jpg) to better show off the fainter nebulosity.  Captured over 5 nights from October 22 to November 1st, 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-290mc for guiding

* Moonlite Autofocuser

**Acquisition:** 14 hours 36 minutes (Camera at Unity Gain, -15°C)

* Ha- 54x360"

* Oiii- 47x360"

* Sii- 45x360" 

* 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:](https://www.youtube.com/watch?v=u7FuApFSGuA)**

* BatchPreProcessing

* StarAlignment

* [Blink](https://youtu.be/sJeuWZNWImE?t=40)

* ImageIntegration

* DrizzleIntegration

**Linear:**

* DynamicCrop

* DynamicBackgroundExtraction

* EZ Decon + Denoise (Ha only)

* STF applied via HistogramTransformaion to bring each channel nonlinear 

**Combining Channels:**

* PixelMath to make classic SHO to RGB image

* SCNR > Invert > SCNR > Invert to partially remove excess greens and magentas

* Pixelmath to make RGB image using [ForaxX's palette](https://thecoldestnights.com/2020/06/pixinsight-dynamic-narrowband-combinations-with-pixelmath)

> R= (Oiii\^~Oiii)\*Sii + ~(Oiii\^~Oiii)*Ha

> G= ((Oiii\*Ha)\^~(Oiii\*Ha))\*Ha + ~((Oiii\*Ha)\^~(Oiii\*Ha))\*Oiii

> B= Oiii

* Pixelmath to blend classic SHO and ForaxX SHO images 40:60

**Nonlinear:**

* LRGBCombination with Ha as luminance

* Shitloads of CurveTransformations to adjust lightness, contrast, saturation, hues, etc.

* LocalHistogramEqualization

* SCNR Green

* More curves

* EZ Star reduction 

* NoiseGenerator to add noise back into reduced stars

* DarkStructureEnhancement

* Extract L channel > LRGBC again for chrominance noise reduction 

* Another round of EZ Star reduction + noise generation

* Resample to 60%

* Annotation

Sessions

Date Ha O3 S2
2021-10-22 0.4 0.4 0.3
2021-10-23 1.1 1.0 1.0
2021-10-27 1.5 1.4 1.1
2021-10-31 1.4 1.2 1.2
2021-11-01 1.1 0.9 0.9
Total 5.5 4.9 4.5

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