Sigma 17-70mm f/2.8-4.5 DC IF Macro Lens for Pentax and Samsung Digital SLR Cameras Large aperture standard zoom lens designed Specially For Digital SLR Cameras. Macro lens level close up ability Minimum focusing distance of 7.9.., maximum magnification of 1:2.3. The new multi layer lens coating and lens design reduce flare and ghosting l Aspherical and SLD lenses, offer excellent correction for various aberrations. The lens offers a large aperture of F2.8 at wide angle.