Any of these images show faint nebulae that haven't been cataloged before (which does not mean that they are unknown). A preliminary list of these objects can be found in a GitHub repository.
Click on the images to see a larger version with description.
OIII arc in Gemini
Milky from Perseus to Cassiopeia
Milky Way in Cassiopeia and Cepheus
HII region around California Nebula (NGC 1499)
Milky Way in Cygnus
Milky Way from Vulpecula to Aquila
Milky Way from Scutum to Ophiuchus
Orion region
Milky Way from Taurus to Perseus
M33 to SH2-126
Milky Way from Monoceros to Gemini
For optimal display, the monitor should be calibrated so that as many shades of the grayscale shown below are distinguishable. At least the 4% steps should be separated by every monitor. The 2% steps are visible on better monitors. To distinguish the 1% steps, a HDR monitor is required.