Processed stars and faint nebula separately in Photoshop and PixInsight. Stacked 265 images together into one. Used software such as Blur Xterminator and Noise Xterminator to help keep the background smooth even with quite a bit of stretching to bring out a very faint dark nebula.

This is the Dark Shark Nebula in Cepheus. It's 265 5-minute images stacked together, or a little over 22 hours of total exposure time. I had to choose a date and time, so I used the details for the first image, but this was actually taken over three nights, about 7+ hours average per night..