If you only darken the region you selected, however, others will notice the boundary between it and the rest of the image. Here’s where the technique of feathering comes in.
Tony Hallas
You’re now at a stage in your processing where the nucleus of Bode’s Galaxy (M81) became too bright. In astroimaging terms, it’s “burned out.” The art of darkening the nucleus area without leaving a trace requires three steps.
