15th Feb 2024: Astro Pixel Processor 2.0.0-beta29 released - macOS native File Chooser, macOS CMD-Q fixed, read-only Fits on network fixed and other bug fixes
7th December 2023: added payment option Alipay to purchase Astro Pixel Processor from China, Hong Kong, Macau, Taiwan, Korea, Japan and other countries where Alipay is used.
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.