As I have previously posted, I have been trawling through my archive looking for likely candidates for the “dehalo” processing i came up with to get rid of those irritating dark haloes around bright objects the PD camera sometimes produces. (I think it is probably an artifact of the PD’s compression/noise reduction algorithms). Again, I’ve already posted some of these. M42 seems particularly to benefit from this:
However, I found this one too, that I was particularly taken by. Here is the original and the dehaloed version.
It is quite simple and quick to do in GIMP and I’ll post the method if anyone is interested, but I suspect it is just my kit and methodology that creates the issue. “Proper” imagers don’t seem to get the problem!