If you want a 50mm - buy the new STM one, S/H it might coast 20% more, but it's 100% better (build quality, focus motor, bokeh)I was also considering a used 50mm canon f1.8 mk2. This end of the range I know little about I live at 400mm plus most of the time. But got the bug of some other things atm. Just found the 70-200 f2.8 was too long or too short.