Sadly LoTr doesn't mean Lord of The rings, but is instead short for the names of the two people who discovered this nebula in 1980, Longmore-Tritton. Wikipedia lists the thing at 1650 light years away from us, and 1.8 ly in diameter. It also happens to be [close to the galaxy NGC 4725 in the sky](https://www.reddit.com/r/astrophotography/comments/mz5kqm/ngc_4725_and_pn_g3399884_in_coma_berenices_19/). I decided to keep this image looking darker overall when processing given how dim the nebula is. Captured over 9 nights from January through March, 2022 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/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:** 32 hours 36 minutes (Camera at Unity Gain, -20°C)
* Oiii- 184x600"
* R- 26x90"
* G- 25x90"
* B 26x90"
* 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) (Oiii only)
**Linear:**
* DynamicCrop
* StarAlign undrizzled RGB stacks to Oiii
* DynamicBackgroundExtraction 2x
**RGB**
* LinearFit RGB stacks to Oiii
* ChannelCombination to make color image from the RGB stacks
* PixelMath to add Oiii to RGB image
> R = $T
> G = 0.1\*Oiii + 0.9\*$t
> B = 0.5\*Oiii + 0.5\*$t
* PhotometricColorCalibration + HSV repair for star color
* Second RGB image created and ran through PCC and HSV repair, for fixing star color later
* ArcsinhStretch + HistogramTransformation to stretch RGB images and Oiii stack to nonlinear
**Nonlinear:**
* LRGBCombination with Oiii as luminance
* Shitloads of CurveTransformations to adjust lightness, contrast, saturation, hues, etc.
* PixelMath to replace the stars with the more color accurate ones from the stars-only image (modified starnet mask used)
> *shockingly* adding the Oiii directly into the G and B channels fucks up star colors, hence this step
* more curves
* MLT noise reduction
* even more curves
* MMT De-blotching
* Resample to 60%
* DynamicCrop
* Annotation
lefty7283
