This is also known as the "eye of god nebula" or NGC 7293, and at 650 light years distance it is the closest planetary nebula to Earth. Wanted to capture the faint outer shells of the nebula, so I ended up getting over 33 hours of exposure time on it. Took a bit of effort in processing to balance the bright core with the outer shells, but overall I'm pleased with the final result. [Also made a starless version for the hell of it](https://i.imgur.com/uo4TJDk.jpg)
Thanks to trees and the fact this nebula only gets 33 degrees up here, I could only photograph it for a maximum of 3 hours per night. Also because it's low in the southern sky I had to [turn off the streetlamp at the end of my driveway](https://gfycat.com/madeverlastingindianpangolin) with a laser pointer while shooting it. Captured over 14 nights from September 2nd to October 20th, 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:** 33 hours 36 minutes (Camera at Unity Gain, -15°C)
* Ha- 175x360"
* Oiii- 161x360"
* 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 (2x, Var β=1.5)
**Linear:**
* DynamicCrop
* DynamicBackgroundExtraction 2x
* EZ Decon + Denoise per channel
* EZ soft stretch per channel to bring nonlinear
**Combining Channels:**
* Pixelmath to make RGB 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
**Creating Synthetic Luminance:**
* linear Ha and Oiii channels stretched slightly with ArcsinhStretch
> This was used to preserve the details in the core of the nebula, which were a little blown out from EZ soft stretch
* Pixelmath to combine the core stretch image with the soft stretch image 70:30 to make a Synthetic Luminance
> mask used just to add this to the brightest parts of the soft stretch image
* Pixelmath to combine Ha and Oiii synth Lums into master super luminance
> Max(Ha, Oiii)
**Nonlinear:**
* LRGBCombination with Synthetic Luminance
* Shitloads of [Curve](https://i.imgur.com/zN7Wsvb.jpg)Transformations to adjust lightness, contrast, saturation, hues, etc.
* EZ HDR
* HistogramTransformation to further stretch the image
* MLT noise reduction
* CloneStamp to remove a severely ringed star that I forgot about during Deconvolution
* more curves
* ColorSaturation to boost the blue in the core
* SCNR Green
* AutomaticBackgroundExtraction
* even more curves
* EZ Star Reduction
* noise generator to add noise back into reduced stars
* another round of MLT noise reduction
* Extract Luminance —> LRGBCombination for background chrominance noise reduction
* MMT noise reduction to reduce background splotchiness
* LocalHistorgramEqualization (nebula core only)
* More curves
* Resample to 80%
* Annotation
lefty7283
