The Butterfly Nebula in HSS Palette

Replies (1)

• @lefty7283@lemmy.world 2025-12-21 19:37

  Not to be confused with the [butterfly planetary nebula](https://en.wikipedia.org/wiki/NGC_6302), this is the one in Cygnus next to Sadr. I shot this thing years ago in [SHO palette](https://live.staticflickr.com/65535/50588757326_5a2a178fe3_o.png), but decided to shoot it again in Ha/Sii since there's very little Oiii in this region. Captured over a bunch of nights in November 2025 from a Bortle 9 zone. **Places where I host my other images:** [Flickr](https://www.flickr.com/people/leftysastrophotography/) | [Pixelfed](https://pixelfed.art/lefty) --- **[Equipment:](https://i.imgur.com/kDRYMKi.jpeg)** * 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:** 22 hours 10 minutes (Camera at -15°C) * Ha - 59x600" * Sii - 74x600" * 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 Preprocessing:** * BatchPreProcessing * StarAlignment * Blink * ImageIntegration per channel * DrizzleIntegration (2x, Var β=1.5) * Dynamic Crop **Narrowband linear:** * MultiscaleGradientCorrection using MARS project data (had to do good ol fashioned DBE for the Sii channel) * BlurXterminator * StarXterminator to completely remove stars (extracted stars processed separately) * STF applied via HistogramTransformation to stretch nonlinear **Stars Only:** * Channel combination to combine stars images into color image * SpectrophotometricColorCalibration (Narrowband working mode) * HSV Repair * ArcsinhStretch + Histogram transformation to stretch nonlinear * Slight saturation curve boost * Stars only image saved for later addition **Nonlinear processing:** * Pixelmath to combine stretched narrowband images into color image (HSS palette) * SCNR > Invert > SCNR > Invert to remove some greens and magentas * DeepSNR * Shitloads of curve transformations to adjust luminance, contrast, saturation, etc * LocalHistogramEqualization * more curves * NoiseX for some small scale chrominance noise reduction * Pixelmath to add in the stretched 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](https://www.nightphotons.com/guides/star-addition)) > mtf(.005, > mtf(.995,Stars)+ > mtf(.995,Starless)) * Slight SCNR * Resample to 65% * Annotation

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