I imaged Gum-15 a while ago and found that it really benefits from lots of integration time. It's not a super-bright object and can disappear into the nebulosity around it, which makes the processing tricky.
May I suggest that you try removing the stars (via starnet++ or similar tool) and working on the stars/no-stars layers separately? I found that it made a huge difference in my final images.
I imaged Gum-15 a while ago and found that it really benefits from lots of integration time. It's not a super-bright object and can disappear into the nebulosity around it, which makes the processing tricky.
May I suggest that you try removing the stars (via starnet++ or similar tool) and working on the stars/no-stars layers separately? I found that it made a huge difference in my final images.
Thanks Max - the background is a bit mucky, but there is a lot of nebulosity in that region, which tends to reduce the contrast across the field of view.