Not an optics expert, what kind of problems can a multitude of more ordinary lenses and software techniques solve? I know there are astronomy cameras that are b

Not an optics expert, what kind of problems can a multitude of more ordinary lenses and software techniques solve? I know there are astronomy cameras that are basically Canon SLR:s with off the shelf lenses. And the signal can be recorded and the resulting bitstreams can be combined in software. I would assume for example surveys work well for a lot of cheap optics+cameras, but for large magnification or faint objects you need one big mirror or lens?