M17 is also known as The Swan Nebula (the bright core is swan shaped, esp when viewed visually through a telescope). Also pictured it the M18 star cluster off to the right.
I originally shot this back in 2019 and decided to reprocess it since we have fun new tools and techniques (and I kinda know what I’m doing now with narrowband processing). I decided to keep the palettes similar overall, but with a less agressive stretch and more ‘natural’ look to the nebula. The noise reduction is a lot better when comparing the images at 1:1 (long gone are the days of TGV/MMT noise reduction!). Captured over 2 nights at the in May, 2019 from a Bortle 7 zone.
Acquisition: 8 hours 10 minutes (Camera at Unity Gain, -15°C)
Ha- 42x300"
Oiii- 56x300”
Darks- 30
Flats- 30 per filter
Capture Software:
EQMod mount control. Captured using N.I.N.A. and PHD2 for guiding and dithering.
PixInsight Processing:
BatchPreProcessing
Blink
ImageIntegration
DrizzleIntegration (2X, VarK 1.5)
DynamicCrop
DynamicBackgroundExtraction
duplicated each image and removed stars via StarXterminator. Ran DBE with a shitload of points to generate background model. model subtracted from original pic using the following PixelMath (math courtesy of /u/jimmythechicken1)
$T * med(model) / model
Narrowband Linear:
BlurXTerminator
NoiseXTerminator
STF Applied via HT to stretch nonlinear
Nonlinear:
PixelMath to combine monochrone Ha and Oiii channels into color image (using ForaxX’s bicolor palette):
Thank you so much for writing all this out. I may not need this information right now (no money for gear) but this is still so intesting. I’ll come back to this when I’ve got the money to spare.
M17 is also known as The Swan Nebula (the bright core is swan shaped, esp when viewed visually through a telescope). Also pictured it the M18 star cluster off to the right.
I originally shot this back in 2019 and decided to reprocess it since we have fun new tools and techniques (and I kinda know what I’m doing now with narrowband processing). I decided to keep the palettes similar overall, but with a less agressive stretch and more ‘natural’ look to the nebula. The noise reduction is a lot better when comparing the images at 1:1 (long gone are the days of TGV/MMT noise reduction!). Captured over 2 nights at the in May, 2019 from a Bortle 7 zone.
Places where I host my other images:
Flickr | Instagram
Equipment:
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
Agena 50mm Deluxe Straight-Through Guide Scope
ZWO ASI-120MC for guiding
Moonlite Autofocuser
Acquisition: 8 hours 10 minutes (Camera at Unity Gain, -15°C)
Ha- 42x300"
Oiii- 56x300”
Darks- 30
Flats- 30 per filter
Capture Software:
PixInsight Processing:
BatchPreProcessing
Blink
ImageIntegration
DrizzleIntegration (2X, VarK 1.5)
DynamicCrop
DynamicBackgroundExtraction
Narrowband Linear:
BlurXTerminator
NoiseXTerminator
STF Applied via HT to stretch nonlinear
Nonlinear:
B = Oiii
SCNR Green
LRGBCombination with stretched Ha as luminance
Shitloads of curve transformations to adjust lightness, contrast, hues, saturation, etc
LocalHistoGramEqualization 2x - one at scale 16 for fine details and one at 512 for large structures
More curves
DarkStructureEnhance
MLT for small scale chrominance noise reduction
NoiseXTerminator
Even more curves, some masked to just the core of the nebula
Resample to 60%
Annotation
Thank you so much for writing all this out. I may not need this information right now (no money for gear) but this is still so intesting. I’ll come back to this when I’ve got the money to spare.