Opteka 650-1300mm (with 2x- 1300-2600mm) Telephoto Zoom Lens for Pentax K-70, K-50, K-3 II, KP, K-1, K-S2, K-S1, K-500, K-30, K5 IIs, K-7, K-5, K-2, K20D, K100D, K110D and K10D Digital SLR Cameras ADVANCED OPTICS: Featuring an optimized design, this lens uses a series of 6 optical glass elements (one SD super-low dispersion) in 5 groups to reduce chromatic and spherical aberrations throughout the aperture range. A high definition anti-reflective coating suppresses lens flare and ghosting for increased contrast and color fidelity. SUPER ZOOM: 650-1300mm or 1300-2600mm with the 2x converter, this lens is not only a superb long range choice, but also performs well in a variety of scenes from sports and surveillance to lunar shots. SOLID CONSTRUCTION: Full metal body and rear mount allow this lens to withstand wear and tear much better than plastic lenses while commanding a rugged, solid feel when using. MANUAL FOCUSING: This lens has preset f-stops that correspond with the focal length at which you are shooting. An index for distance and diaphragm scale is inscribed on the lens barrel to coordinate focal length and aperture. COMPATIBILITY: Can be used on all Pentax APS-C and full frame cameras including K-70, K-50, K-3 II, KP, K-1, K-S2, K-S1, K-500, K-30, K5 IIs, K-7, K-5, K-2, K-r, K-x, K-m, K20D, K200D, K100D, K110D and K10D.