this image has been considerably downsampled/compressed for LB. full(er) res here: https://live.staticflickr.com/65535/52569658686_3e428ed90c_o.png
At 101 hours 6 minutes, this is the longest exposure time I've put into a single object (albeit across 6 panels), beating out my previous record of [84 hours](https://www.reddit.com/r/astrophotography/comments/y6u89i/sh2224_supernova_remnant_in_auriga/). I had shot [just the elephant trunk itself](https://www.reddit.com/r/astrophotography/comments/qhc5tm/the_elephants_trunk_nebula_sho_palette/) last year, and this year I decided to revisit it, and shoot a mosaic of the entire nebula. Due to my limited horizons at my new apartment (just a sliver of the northwest sky) and a stupidly clear fall, I made 100 hours of exposure time my arbitrary goal for this pic
This photo was downsampled to 65% of it's original 276 Megapixel resolution, which puts it *just* under Flickr's 200MB upload limit. All panels were shot over the course of 33 nights spanning September to November, 2022 from my Bortle 8 apartment balcony.
**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:** 101 hours 6 minutes (Camera at Unity Gain, -15°C)
* Ha - Roughly 5.5 hours of 360" exposures per panel
* Oiii - Roughly 5.5 hours of 360" exposures per panel
* Sii - Roughly 5.5 hours of 360" exposures per panel
> [Exact exposure breakdown here](https://i.imgur.com/pXgopjI.png)
* 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)
**Creating the Mosaic:**
> For whatever reason mosaic by coordinates refuses to work for me despite updating/reinstalling pixinsight, or even downloading the script directly from others.
* DynamicCrop to remove stacking artifacts
* Several rounds of automatic and dynamic background extractions to remove gradients
* LinearFit
* Exported photos as tiff, stitched in Microsoft ICE per filter
* StarAlign stitched Oiii and Sii images to stitched Ha
**Linear:**
* DynamicCrop
* DynamicBackgroundExtraction
* EZ Decon
* NoiseXTerminator
* STF applied via HistogramTransformation to stretch nonlinear
**Combining Channels:**
* PixelMath to map Sii, Ha, Oiiito RGB, respectively
**Nonlinear:**
> I did this over the course of several days and a couple crashes so this isn't exhaustive, but I believe this is mostly what I did in order
* HistogramTransformation to pull back the green channel and slightly boost red
* LRGBCombination with extracted L as luminance
* Invert > SCNR > Invert > to remove some background magenentas
* Shitloads of CurveTransformations to adjust lightness, saturation, contrast, hues, etc. with various masks
* NoiseXTerminator
* More Curves
* LocalHistogramEqualization
> Two rounds of this. one at size 16 for the finer 'feathery' details and one at size 500 for large scale structures
* DarkStructureEnhance
* Even more curves
* ColorSaturation to better bring out the Oiii regions and desaturate background reds/magentas a little
* More NoiseX
* curves
* Inverted SCNR with a starmask to remove magentas from stars
* EZ star reduction
* NoiseGenerator to add noise into reduced star areas
* guess what more curves
* Resample to 65% (any image larger than this is too big for flickr)
* Annotation
lefty7283
