Summary: Absolutely stellar. The build quality is superb. The manual focus is smooth and consistent which makes close macro work much easier. given its reach (100mm) and bright aperture (f/2.8) the lens is surprisingly compact.
Summary: This is the sharpest lens I have no doubt about it, the contrast and colors are also excellent. It would be my favorite Pentax lens but I hardly ever use that focal length. (150mm on ASP-C). On the negative, it can be a little long for some macro work.
Summary: Have to echo other reviewers here... Too many pros and only a few cons. These first: Too specialist of a lens - because of that 1. hard to autofocus - long focus travel makes it tough when it doesn't lock right away it takes a while for the 2nd try because the focus travel is really long, you...
Best price (as of 11-5-14) I've EVER SEEN on this INCREDIBLE lens that's also FF compatible!
Jeff Hayes, Amazon
5 November 2014
Summary: I've owned this lens since September 2011, and it's one of the best lens purchases I've ever made. At the time I paid $620, and got what I considered a decent deal, as the MSRP on it was $749 at the time (I think).