I have an older Canon Rebel XS camera and three lenses. 18-55mm f3.5-5.6, 75-300mm f1.4-5.6, and a 50mm f1.8. I am just getting interested in night sky photography and got some good shots of the Super moon last fall using the 75-300. I was wondering which of these lenses would be best for Milky Way and constellation shots? Photography budget is N/A at this time so need to use what I have. I think the 75-300 would let in the most light, but was wondering if the 50mm would get more night sky? Anyone have any ideas for me?