Here is my Extreme Close-up of M57 with a ZWO ASI224MC un-cooled Color Cmos Camera using short exposures stacked.
The Ring Nebula, also known as M57 or NGC 6720, A dying Star, blowing off its outer atmosphere. M57 is found in the constellation Lyra. A spherical shell of glowing gas surrounds a central hot star. The nebula was formed when the central star ejected some of its mass. Initially slow mass loss creates a surrounding shell of material which is later ionized by hotter, faster ejecta, which can result in quite complex structures. The Ring Nebula was the first planetary nebula discovered, so called because of its visual spherical appearance through early telescopes . M57 has a diameter a little under one light-year and is some 3000 light-years from Earth (angular size 1.2 arc minutes). Taken with my old orange tube C-11 Telescope & Software Bisque MyT Robotic Tracking Mount, ZWO ASI 224MC un-cooled Cmos Camera & short exposure stacking imaging technique, from my backyard observatory in Dayton, Ohio on 08-09-2020.
I visually examined & filtered through over 220 frames, to choose the best frames, ended up with 161 good frames to work with. 161 x 10 sec. exp.= 26.83 minutes total, Subtracted Master Dark frame = 63 x 10 sec Dark frames, using Fire-capture Software, Registax6, Nebulosity, and Adobe CS.
Best Regards,
John Chumack