[AdamJL]

Hi all

I'm starting to learn PixInsight, and working my way through some tutorials.

Right now, I'm still in the linear data phase, and I'm going to do a star reduction using MorphologicalTransofrmation after using a starmask (that I had to set to about 0.23 to get it to pick up the right stars).

However, after doing a very light (one!) pass, I see some mottling in the image

See first attachment. Picture on the left is the before, picture on the right is the after.

What causes this mottling? The star reduction works well, was it the mask itself? Is this normal and I'm only seeing it because the stars reduced fairly well?

TIA for any help