Sigma 17-35mm f/2.8-4 EX DG IF Aspherical Super Wide Angle Zoom Lens for Pentax and Samsung SLR Cameras 17mm Ultra-Wide-Angle to 35mm wide-angle zoom lens for Pentax AF cameras 11.5x total magnification Focuses as close as 19.7 inches at all focal lengths and as far as infinity Aspherical lenses maximize optical performance in a smaller and lighter design Perfect hood reduces light glare