I'm just begining to learn the different techniques required for processing images of deep space objects. In the image below the nebulosity was extracted as a seperate image from the stars. My approach was slow, but I've found software that will speed this up in the future. Once the images are seperate processing can be optimized for each. In this case heavy stretching and noise reduction in the nebulosity. It's hard to pick up nebulosity when the gas is only illuminated by hydrogen emission, because this deep red color is filtered out by IR filters on commercial cameras. Most images of these targets are made with special astronomical cameras or commercial cameras modified to capture light the Hydrogen alpha emission line. However standard cameras do capture some of this light and it's been a fun challenge to work with the Horsehead Nebula under a bright urban sky. My first try at this sort of processesing is below:

A nice improvement from my earlier tries with this data. I'll revisit this subject when I get some clear dark skies and four hours of exposure time.k

William Optics RedCat 250/51 mm f/4.9 with a full frame Sony a7 iii camera and an Astromania Moon & Skyglow filter exposing 132 30 second frames at ISO 3200. Stacked in Nebulosity with processing and exposure stretching in PixInsight and Photoshop.