• lefty7283@lemmy.worldOPMEnglish
    2·
    10 days ago

    Not to be confused with the butterfly planetary nebula, this is the one in Cygnus next to Sadr. I shot this thing years ago in SHO palette, 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 | 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: 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. 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)

      mtf(.005,

      mtf(.995,Stars)+

      mtf(.995,Starless))

    • Slight SCNR

    • Resample to 65%

    • Annotation