Built to meet the rigorous demands of professional photographers, the HD PENTAX-D FA 24-70mm f/2.8ED SDM WR is sure to become your go to lens! It’s designed to deliver speed, sharpness and performance, while producing a beautiful soft bokeh (defocus) effect on the background throughout the entire focal range. Providing a constant aperture of f/2.8 over the entire zoom range, this fast versatile zoom lens greatly reduces the need for a tripod when photographing subjects in less-than-ideal lighting conditions, such as sunsets and indoor scenes. By incorporating three ED (Extra-low Dispersion) optical elements and four aspherical optical elements, it assures sufficient light levels even at the edges of the image field and compensates various aberrations to a minimum to deliver well-depicted, fine-detailed images, rich in contrast and resolution. The built-in SDM (Supersonic Direct-drive Motor) provides quiet, high-speed autofocus operation.