Aside from the DFA 15-30mm, this is hands down the best UWA zoom for Pentax full-frame digital. This copy is in beautiful mint condition, and has been on and off the camera about 5 times since new (one owner). It's essentially new-old-stock, everything is as-new.

This is definitely one of Sigma's better lenses from the late film/ early digital era- it's extremely sharp in the center from wide open, resists flare very well, very nicely dampened manual focus, and the CA and distortion that do exist are predictable and very easily removed in software.

Optically perfect, everything is clean.

This lens is also compatible with all pentax k film bodies due to having an aperture ring