While not in the same league as M&T's 70 odd hour epic, this is my deepish
take on the Helix nebula.
Still a work in progress, with the intention of adding OIII plus RGB data as the weather allows.
I decided to try using my QHY600M on this, but have been be-devilled by low level banding which, even with epic dithering,
has still not delivered a CCD-smooth sky...,but has picked up some remarkably faint stuff (the lower left chevrons and upper left shock fronts).
It was however very satisfying to see the data I was getting from the 'burb's was consistent with M&T 20" CDK version.
Quite a few "deep" images on the web have suspect processing that show nebulosity in places where there is absolutely none.
The link is here