I have had great results with the Zeiss 50 1.4, C/Y mount. $250 - $350 oneBay. Gorgeous images from flowers to portraits and probably anything else. I also have the Pentax 50 1.4 Tak which can be had for around $100.00 or less and arguably as good as any Leica or Zeiss lens at the time (1960's). Check out the Canon FD's as well. You simply can't go wrong with the above 3 lenses.