on crop sensor i'm highly recommend get the 50mm f1.8 or f1.4d or G model. It's better work on crop sensor. If the 85mm f1.8 is not that good, cause distance too far, just take the head portion. For 50mm back 5 step still can take whole of body. Why not try for 50mm in crop sensor. If FX i will prefer u to get 85mm f1.4 it's better sharpness than f1.8d.