Finally you will have a new set of pre-processed light frames, automatically loaded in Siril, that you could register. Please note that at this stage you always have a lot of noise in your image. Indeed, pre-processing images with Dark, Bias and Flat do not remove noise but unwanted signal. The following Picture shows you the result of demosaicing. It is displayed in Auto-stretch visualisation mode in order to enhanced the visibility of signal but without altering your image.