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LP filter & Star calibration problems
I've recently started using a CCD-CLS light pollution filter and whenever I do the star calibration step the nebula(s) turn yellow. I am not using false color and I would really like to keep the reds red. I can't get back to the original color with the Selective Color Tool and I am hoping that someone knows how to correct this when it happens.
I'm not sure if my approach is correct. In my opinion, APP tries to balance the lost colors that blocked by CLS filter.This resulted in yellowish in your red nebulae. My approaches to correct would be changing calibration mode from the default 'Adaptive Black Body & Extinction' to 'Balance RGB', or adjusting the slider balance between blue and red. However these will affect your star colors as well. My third method is to accept what APP giving by default and correct hue, saturation, and luminance during post processing in Adobe Lightroom. One thing to remember is we needed to remove the light pollution as good as possible before star color calibration. Because light pollution also contains unbalance colors.