Sigma 17-70mm F2.8-4 Contemporary

General Image Quality

We found the image quality of the Sigma 17-70mm "Contemporary" to be excellent overall.  The lens controls aberrations very well, produces smooth bokeh, is sharp across the board, and has minimal vignetting.  Its biggest weakness is distortion, which is prominent and can unfortunately not be corrected in-camera (as Pentax DSLRs only have lens correction profiles for Pentax DA, DFA, and FA Limited lenses).  More details on the optical performance of this lens can be found on the next five pages of the review, which contain test photos and offer additional conclusions.

You will hardly ever miss a shot with this lens due to its versatility.  It can be used for portraits, macros, landscapes, cityscapes, family photos, pets, and more!  Best of all, the lens is actually good at fulfilling all of these roles, and you can expect quality photographs from it.

We found it to render colors accurately and without the yellow color cast that we observed with the older Sigma 17-70mm lenses.

Thus, overall, we see this lens as the ultimate kit lens replacement for Pentax DSLR owners!

Macro Mode

The 17-70mm is able to focus on subjects as close as 22cm away, with a maximum magnification of 1:2.8.  This degree of magnification is perfect for hand-held close-ups of flowers, insects, and plants.  Thanks to the relatively-fast maximum aperture at both ends of the zoom range, this lens also gives you a significant amount of control over the depth of field and the bokeh.

Sample close-up photo @70mm (Click to enlarge)