Combination of 10, 3 minute exposures.
SBIG STL-1001E CCD. 20" f/6.8 Dall-Kirkham cassegrain telescope at prime focus.
Abell 54 is a large but extremely faint planetary nebula in Vulpecular. Like all Abell planetaries, it has a very low surface brightness. Even after 30 minutes total exposure with a 20" telescope, only the faintest traces of the planetary are visible in the image above! (indicated by the white lines)