Pentax 85mm f/1.4 IF SMC P-FA
(From Pentax lens literature) The Pentax SMC P-FA 85mm f/1.4 IF is a great portrait lens. It allows for a shallow depth of field and is ideal for working in low-light conditions. It features an internal focus system to make focusing smoother and faster, and is treated with the acclaimed SMC coating for maximum light transmission, sharp definition, and high contrast while minimizing flare and ghost imaging.
Pentax 85mm f/1.4 IF SMC P-FA User Reviews
10 out of 10 points and recommended by elho_cid (10 reviews)sharpness and contrastbokeh fringing, no close focus
I was a bitt worried by the FL, as I thought it might be too long on APS-C. But it is not a problem. I'm happy to choose this portrait lens as the DOF wide open is amazing and still I get great shapness. At f1,7 contrast kicks in and it is so sharp that even in the edge of the image I get moire artifacts with K10D.reviewed March 6th, 2011 (purchased for $1,150)
At f2,4 it essentially burries dead the poor little DA70 that I considered before.
Build quality is also great and with K-5 I can autofocus precisely even f1.4. Also surprisingly fast to AF, I tried shooting seagulls flying around and with great success.
Most recommended lens!