Reviews and Problems with Sigma 50-200mm F4-5.6 DC OS HSM
Showing 1-1 of 1
Sigma 50-200mm f/4.0-5.6 DC IF SLD Optical Stabilized (OS) Lens with Hyper Sonic Motor (HSM) for Pentax Digital SLR Cameras
19 January 2012
Summary: Unfortunately, the vendor did not fully test compatibility of this lens with all Pentax cameras. Thus, while it appeared to be a nice lens, the autofocus function was inoperable on my Pentax K10-D. I thus returned the lens since the manual focus ring on the lens did not operate smoothly. It wasn't enough of a good deal for me to forgo the autofocus function. I'm sure it's a fine lens not just for K10-D owners.