Canon rf 50mm f 1.8 stm lens vs ef July 8, 2019 16 32 64 128 Canon rf 50mm f 1.8 stm lens vs canon ef 50mm lens specs Canon rf 50mm vs ef 50mm Canon ef 50mm 1.4 vs rf 50mm 1.8 Canon ef vs rf lens Canon rf 50mm 1.8 astrophotography