This has been one of my more difficult images to process. I wanted to highlight the faint outer ring captured in narrowband, but still include the LRGB data for the bright nebula core. I struggled to blend the faint and bright parts of the image together, and due to this the data has been sitting on my hard drive for over a year unprocessed. This was the last Messier I had to finish to complete my catalog, so I decided to just brute force my way through processing it. Although it still looks a little unnatural, I'm happy with how it's turned out. I'm surprised how much detail in the core I was able to get out, despite shooting at a focal length of 610mm (all filters were 3X drizzled). Captured over several nights from March through June, 2019 from a Bortle 7 zone.

**PixInsight Processing:** (I *think* I got everything down)

* BatchPreProcessing

* StarAlignment

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

* ImageIntegration

* DrizzleIntegration (**3X**, VarK=1.5)

* DynamicCrop

* DynamicBackgroundExtraction 2X

**Creating narrowband superluminance**

* LinearFit Ha to Oiii

* PixelMath to combine channels

* The goal was to have the Ha weigh more on the faint outer ring than the Oii

> iif(Ha<0.01, 0.8*Ha+0.2*O3, 0.2*Ha+0.8*O3)

* TGV+MMT noise reduction using Darkarchon's script

* HistogramTransformation for aggressive stretch to nonlinear

**Luminance**

* Deconvolution

* TGV+MMT noise reduction using Darkarchon's script

* HistogramTransformation for mild stretch

**RGB**

* LinearFit to green

* ChannelCombination

* PhotometricColorCalibration

* SCNR

> Image cloned twice at this point, one for HaOiiiRGB outer ring detail and one for Stars. Original image used for RGB_Core.

* ArcsinhStretch/HistogramTransformation for mild stretch

* LRGBCombination with stretched luminance

* Color Curve tweaks

**RGB Stars**

* HSV repair

* ArcsinhStretch/HistogramTransformation to stretch stars

* CurveTransformations to adjust colors

**Ring core**

**Outer Ring HaOiiiRGB**

* Cloned RGB and linear Ha combined using NBRGBCombination

* ArcsinhStretch/HistogramTransformation for agressive stretch

* LRGBCombination with stretched Ha+Oiii superluminance

* Curves for tweaking outer shell colors

**Combining outer ring + Core images**

* PixelMath to add in slightly stretched core to outer ring (core mask used)

> Ring_Core\*0.9+0.1*$T

* PixelMath to add in stretched RGB stars over existing stars

* Several more CurveTransformations

* LocalHistogramEqualization

* ACDNR

* MorphologicalTransformation

* Annotation

* Resample to 90%