https://www.youtube.com/watch?v=1Wd7VxpMCH4

1. Extract Ha data you want

   1. calibrate Background of Ha & Red

   2. Remove Stars from Ha

   3. S1 = Factor, ca. 0.25

      HaNEW = Ha - Red * S1
      

2. Add desired Ha data to Red or Luminance data

   1. S2 = Factor, ca. 1.0

      RedNEW = Red + (HaNEW - med(HaNEW))*S2