The smc PENTAX-DA* 50-135mm f/2.8 ED (IF) SDM Lens from Pentax is a telephoto zoom designed for APS-C-format K mount DSLRs, where it will provide a 76.5-207mm equivalent focal length range. Three extra-low dispersion elements are incorporated within the optical design, which help to reduce chromatic aberrations and improve clarity and sharpness. Benefitting handling, the constant f/2.8 maximum aperture ensures consistent performance throughout the zoom range and also enables working with shallow depth of field and selective focus techniques. This lens also features an SDM autofocus motor that provides quick, near silent focusing performance and a Quick Shift Focus System for instantly switching between manual and autofocus operation.
