Masters of PixInsight tutor Warren Keller will guide you through a challenging aspect of narrowband imaging: equalizing the lightness in the three narrowband filters (SII, OIII, and Ha), which can vary widely depending on the target.
Starting with your stacked data of these three narrowband frames, Warren will discuss and compare various methods such as MTF, LinearFit, and Narrowband Normalization PixelMath expressions by Bill Blanshan. These techniques are used to better balance the color channels in a combined RGB image.
To install the script, add this URL to your PixInsight repository:
https://www.cosmicphotons.com/pi-modules/narrowbandnormalization/