Kronberger 20 (Kn 20, DSH J2021.4+3005, PN G069.7-03.7) Planetary Nebula in Cygnus. Taken over
several nights from Aug 03, 2021 through Sept. 10, 2021. Imaged with Starlight Xpress’ SX-825 camera
and a Celestron EdgeHD 9.25 at f10, on a Losmandy G11/Gemini mount. The H alpha and OIII subframes
were 20 minutes binned 1x1, while the RGB subframes were 4 minutes binned 2x2, resulting in the
following total exposures L:R:G:B = (HA+OIII):(R+Ha):(G+OIII):(B+OIII) (min) = (520+ 600):(64+520):
(64+600):(64+600). Captured with Nebulosity, calibrated, sigma combined in Iris with other
processing using PixInsight LE and Photoshop CS. North is up.