Another pic from my recent dark site trip! Decided to shoot something bright and in true color LRGB. If I had stayed another night and gotten more data I probably would've pushed the image more to get more background details, but overall I like this darker look on the image. Last time I shot this nebula was in 2022 using the false color OSH palette). Captured on July 26th, 2025 from a bortle 3 zone (deerlick astronomy village).

Places where I host my other images:

Flickr | Pixelfed

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, Sii 5nm

• Agena 50mm Deluxe Straight-Through Guide Scope

• ZWO ASI-290mc for guiding

• Moonlite Autofocuser

Acquisition: 4 hours 2 minutes (Camera at -15°C), half unity gain

• L - 49x120"

• R - 267x120"

• G - 23x120"

• B - 23x120"

• Darks- 30

• Flats- 30 per filter

Capture Software:

• Captured using N.I.N.A. and PHD2 for guiding and dithering.

PixInsight Preprocessing:

• BatchPreProcessing

• StarAlignment

• Blink

• ImageIntegration per channel

• DrizzleIntegration (2x, Var β=1.5)

• Dynamic Crop

• 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

Luminance Linear:

• Blur and noisexterminator

• Stars removed with starx

• ArcsinhStretch + HistogramTransformation to stretch nonlinear

RGB Linear:

• ChannelCombination to combine monochrome R G and B images in to single color image

• SpectrophotometricColorCalibration

• BlurXterminator (correct stars only)

• HSV Repair

• Extracted stars with starXterminator, to be used later for independent starless processing

• ArcsinhStretch + HistogramTransformation to stretch nonlinear

• Slight saturation curve boost

** Stars only processing:**

• ArcsinhStretch + HistogramTransformation to stretch nonlinear

• Slight SCNR to remove greens

• Curves to boost saturation

Nonlinear Processing:

• LRGBCombination to combine stretched RGB and L images

• NoiseX again (more for chrominance noise)

• Several rounds of curve adjustments for lightness, contrast, saturation, color balance, with various masks

• LocalHistogramEqualization (one at 16 scale for fine details, and another round at ~300 scale for larger structures)

• More curves

• Color Saturation

• Even more curves

• Slight SCNR on the background

• Pixelmath to add in the stretched RGB stars only image from earlier

  This basically re-linearizes the two images, adds them together, and then stretches them back to before. More info on it here)

  mtf(.005,

  mtf(.995,Stars)+

  mtf(.995,Starless))

• Resample to 80%

• Tighter crop in on just the nebula

• Annotation