I processed the stars and the nebulosity separately in PixInsight and Photoshop, but didn't change much. Just brought up the light and the color.

This is five hours of NGC 2238, the Rosette Nebula, with the open star cluster NGC 2244 in its center. I actually started shooting around 11:45, in 5-minute increments, and kept going until the sky got too light at 5:30-ish.