AF on this lens has been an issue out there, perhaps more so for other platforms. I would do a Google search, as I have read complaints from Canon and Nikon users.
I had very mediocre AF performance on this lens (it would not lock and would keep trying for too long) until I adjusted the AF in the K20D. Now the AF is quite good, but not quite as good as with most of my other Pentax AF lenses (the FA 50mm also needed some adjustment, but not as severe as the Tamron).
Like others, AF is not all that important to me; unfortunately the lack of a QuickShift function means that it has become more important. A trick is to press in the lens release button and you can "quickshift" the focus when needed. Not perfect but functional.
M
Originally posted by zenkinsw hi guys,
I am also interest in Tarmon 17-50, currently owned the Pentax 16-45.
I'm wondering, how's the focus accuracy and speed on Tarmon lens compare to Pentax?
I am really happy with the 16-45 pictures quality, but really want a fast zoom lens for indoor or events shooting.