Full quality processing on Astrobin here.
The California Nebula (NGC 1499) is usually thought as an Ha emission nebula, but it also has a significant SII signal (but OIII is almost absent, at least in the area above). It also has a few interesting dark structures, the most prominent being in the image (top center).
With 2.5° of length, or the angular size of 5 full moons, it is a very large object, often portrayed in wide field images.