A very short integration M17. Wanted to see what I could get in 4 hours from a roughly Bortle 6/7 sky with my 8” f4 Newt. Was a little cloudy and windy so got 2.75 hours all up. Processed in PixInsight, where I decided to strip the green out of the image (meaning Ha became a kind of yellow/orange, against the OIII Blue and SII Red). Stars are narrowband coloured too but removed the magenta by inverting the image and removing the green (the inverse of magenta).
Scope: Skywatcher 8” F4 Newtonian
Camera: ZWO ASI1600MM-Pro (gain 200, -10°)
Mount: Skywatcher EQ6-R
Ha 5nm 22x180s, [OIII] 3nm 17x180s, [SII] 3nm 16x180s
More details and larger image here:
https://www.astrobin.com/full/pkl3hj/0/