UPDATE FROM MABULA
I have had a very rough 2 months unfortunately health wise. I was struck 3x in a row with bacterial infections. The second infection occurred  after a routine hospital checkup and I became very sick. I had to rest and take a lot of antibiotics. Once I was recovering and restarting work 1 month ago, I again became sick. The infection was not yet gone, so even more antibiotics and rest was needed. Needless to say, it took a lot of my energy and I needed a lot of rest.
Finally, the infection is really gone and my energy is coming back step-by-step now and I have started work again. I am terribly sorry to have kept you waiting for support. I will address all outstanding questions and e-mails step-by step and will be on the forum daily from today.
APP 2.0.0-beta47 will come soon as well, a lot of work was already completed before I became very ill, so the release is also nearly ready for you. Beta47 will be much faster actually. Many workflows will be more than 2x faster, mosaics can even be 10x faster than before because registration really received a major boost... all compared to beta46. Â Before I release it, I will make sure that everything is working properly and then I will release it.
Let's say that I have a total of nine hours of M81: three hours from a Bortle 6 site, three hours from a Bortle 5 site, and three hours from a Bortle 4 site. Furthermore, let's say that I use the same scope, camera, exposure and gain. If I were to process these together to make one final image, can I sort-of expect that it would be equivalent to capturing all nine hours at the Bortle 5 site in terms of SNR? Is there a "gotcha" that I don't understand? Clearly, the background sky ADU will be different at each site. Does APP "normalize" this out?
Thank you!
So it will help to combine all this data and get better signal for sure. However, the quality of the data from the sites with more light pollution will affect the end result. So yes, it'll be better and normalised nicely, but there will be more noise and less signal compared to having all 9 hours at the darkest site.
