This is the first proper image with my new Astrodon filterset! They were delivered with a month of complementary clouds, of course
A couple hours of my clear sky time were wasted due to unfortunate mistakes, I should not experiment with new things in SGP during good nights. The gain was also supposed to be set to 200 for the Ha subs, as gain 75 is definitely not ideal for 5 min subs with the 3 nm filter. Green subs were not corrected well with flats, so I used DBE instead to flatten the green master.
Compared to my ZWO filters, the color balance of the Astrodons appears to be slightly different with more H-beta in the blue channel and slightly different star colors. Pure RGB is shown in Rev. G (or mouse-over of Rev. F).
The optics of my refractor don't correct very well near the UV end and I still need to use a Baader UV/IR block filter in front of my reducer to correct star bloat in the Astrodon blue and luminance filters. I think that the halos around bright stars are due to the 2" UV/IR filter, Astrodons should produce no visible reflections.
Combining the faint blue reflection components of IC405 with the intricate Halpha structures was not trivial. I processed the RGB and Ha separately, then blended a starless version of the Ha in the red and blue (20%) channel of the stretched RGB data, effectively creating a (HaR)G(HaB) image. Ha was then used as luminance (70%) on a copy of the data, labeled Ha-(HaR)G(HaB).
To correct the stars and blue reflection components, I created another copy of the RGB and brightened it a bit further. Next, I made a mask from the blue data and then used this mask plus PixelMath to add the slightly brighter RGB to the Ha-(HaR)G(HaB) image.
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