Roger’s further processing of my M101 image from last night

I often get a similar effect (green images) with the PD when I am doing an extreme stretch. I put it down to a cheap camera! I reduce it by stretching the luminance only and then trim it using “curves” on the individual colours. However, the GIMP light pollution routine you posted does a pretty good job. What do you think of this? I simply used repair or clone on the main galaxy despeckled layer before setting its mode to subtract.

Process used in detail:

1. Duplicate image
2. Despeckle top layer – set radius to max, black to 0 white to max uncheck recursive and adaptive.
3. Despeckle layer now has blob over M101. Get rid of it using clone or repair
4. Set mode of despeckle layer to subtract
5. Merge down
6. QED

Roger