im new to photography and have heard these “nifty fifty” lenses are great for portraits and as a regular go to lens. I want to take pictures of my infant son and am trying to find a good one and am torn between these two.. I have a canon sL2 and have the kit lens as well as a 18-250mm.. I know that with a crop sensor vs a full frame, lenses actually have different focal length (a 50mm is actually like a larger length) I may have that wrong but. Any advice will help. I’m also really interested in getting into astrophotography, landscape and macro. I know neither one of these lenses are good for them but...thanks!!