A more traditional approach, starting with a HOO image, added the S2 as gold/yellow with NBCoulorMapper, and then merged it with a the full LRGB image (not just the stars).

Acquisition details in post below.

by Wide-O

1 Comment

  1. **Acquisition and Processing Information**

    **Equipment:**

    * OTA: W.O. BlackCat 91
    * Mount: AM5N
    * Camera: ZWO 2600 MM
    * Filters: SHO Antlia 2.5nm, LRGB Optolong
    * Controller: Asiair Plus
    * Guide camera: ZWO ASI220M
    * ZWO 2” x 7 Filterwheel
    * ZWO OAG L
    * ZWO EAF

    **Subs:**

    * captured in November & December 2025
    * 24 x 5 min S, gain 100
    * 24x 5 min H, gain 100
    * 24 x 5 min O, gain 100
    * 4 x 20 x 1 min LRGB, gain 0
    * Darks/Flats/Bias
    * Bortle 6-7

    **Processing:**

    * all processing in PixInsight
    * WBPP
    * SpectrophotometricFluxCalibration/MultiscaleGradientCorrection
    * SpectroPhotometricColorCalibration in narrowband mode for SHO, and normal mode for the LRGB stars
    * DynamicCrop, BlurXT, StarXT, NoiseXT, GHS, CurvesTransformation
    * LHE (2x), UnsharpMask, DarkStructureEnhance
    * SHO: Hubble palette did not give me a satisfactory result, as the Ha was overpowering the Sii, so I made a
    * Stars: LRGB

    I’m usually a fan of the Hubble palette, but it did not work well for this image, so I decided to go for the more traditional HOO route. I then added the S2 via NBColourMapper as a gold/yellow.

    Adding just the LRGB stars obtained with SXT did not give a pleasing result, until I tried to add the full LRGB version, which brought out more of the halos on some stars, which I liked in this case.

    Knocked down the smaller stars with MorphologicalTransformation.