I am fairly new to astro imaging, but I enjoy this immensely. I hope you don’t mind this newbie question, but why does stacking in Siril increase brightness? I though, stacking would just reduce the signal to noise ratio.
As you can see in the attached image, the more I have to stack for a given region, the brighter the picture becomes. This results in highly visible edges when the source frames are not perfectly aligned.
Why is this the case with stacking? It not only improves signal to noise, but also brightness?