It's been a few years since I last shot this cluster, so I decided to revisit it. Using the same gear as I did [last time](https://www.reddit.com/r/astrophotography/comments/b07wy6/m13_the_great_globular_cluster_in_hercules/), however I have less light pollution where I'm at now, better processing skills, and a bit more total exposure time. Captured on May 9th and 10th, 2022 from my Bortle 6 driveway.
**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/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:** 2 hours 40 minutes (Camera at Unity Gain, -15°C)
* Lum- 59x90"
* Red- 17x90"
* Green- 15x60"
* Blue- 16x60"
* 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://youtu.be/E6vj_SEZ79k)**
* BatchPreProcessing
* StarAlignment
* [Blink](https://youtu.be/sJeuWZNWImE?t=40)
* ImageIntegration
* DrizzleIntegration (2x, Var β=1.5)
**Linear:**
* DynamicCrop
* Dynamic Background extractions
**RGB:**
* ChannelCombination to map monochrome R, G, and B images into a color image
* PhotometricColorCalibration
* Slight SCNR green
* HSV repair
* ArcsinhStretch + HistogramTransformation to bring nonlinear
**Luminance:**
* NoiseXTerminator
* ArcsinhStretch + HistogramTransformation to bring nonlinear
**Nonlinear:**
* LRGBCombination with stretched L as luminance
* Several curves transformations to adjust lightness, contrast, saturation, etc
* MultiscaleLinearTransform for large scale chrominance noise reduction
* SCNR green
* More Curves
* Resample to 80%
* Annotation
lefty7283
