This is a 4 panel mosaic in the vicinity of the MW's core with a modified Canon T2i and a Canon 50mm STM lens at f4. There is a ~40% overlap between panels and the  exposure time for each panel is variable between ~ 1 hr and ~ 1 hr 20 mins.

The mosaicing required some planning as certain parts of the image get an altitude of only ~15 -20 degs above horizon from my latitude. So an open east-south horizon was needed. This limits me to mostly desert areas in California where summer temperatures (when we best see the MW core) are extremely high and unbearable for both me and my DSLR. So, I decided to map this region as it was rising just a few hours before sunrise in the Spring when desert temperature has not gone up yet. The imaging was done over two sessions under Bortle 3 (Joshua Tree National Park) and Bortle 2 (Fossil Falls campground) skies but both sites have light pollution at the horizon where I imaged the Milky Way. The Bortle 3 sky was very transparent at the time as it had rained there the night before. The Bortle 2 site was a bit hazy and much brighter than usual (I have been there before and never seen it that bright). Too much airglow and/or atmospheric scattering? I do not know.  Also, the overall imaging area was close to the horizon. Guiding  accuracy was sub-arcsec at the Bortle 3 site and ~1.5"-2" rms at the Bortle 2 site. Given the moderate exposure times and the observing condition, I did not expect a good result but I am totally satisfied with the outcome.

I used APP for preprocessing and making the mosaic. The post-processing was done with APP and GIMP. I tried Starnet++ but it created several giant and completely dark regions in the mosaic and messed up the color balance as well, so I gave up on it eventually. I tried other tricks to have a better control over the stars. I could have stopped down the lens a bit higher than f4 as it still shows some chromatic aberration and coma but it is not terribly bad. A tad of Topaz denoise was also used at the end. The output tiff file is huge (~400 MB) so I used a ~26 MB jpg version here.