Visual deep-sky observing notes and sketches
Elevation 800 m, telescope D = 508 mm, F = 2000 mm. Sky 21.42 mag/sq arcsec, seeing 1 arcsec. Abell 22, planetary nebula in CMi. Ocular 13 mm, OIII filter. The nebula is a puff of light immediately NNW of a faint star.
