Get yourself to Ebay! A Pentax-A 50mm F1.4 is a great portrait lens on a K-5, probably $100. If you need AF you're looking at twice the price or more, but you c

Get yourself to Ebay! A Pentax-A 50mm F1.4 is a great portrait lens on a K-5, probably $100. If you need AF you're looking at twice the price or more, but you could get something slower. For a zoom something modern is a better idea, but old primes are still pretty great.