This dynamic HD-DA 16-50mm f/2.8ED PLM AW Lens from Pentax is a classic wide-angle to portrait-length zoom lens with a constant f/2.8 aperture through the entire zoom range that delivers optical performance and is an ideal regular-use lens. It incorporates a newly designed optical system and an advanced Pulse Motor (PLM) to assure smooth, high-speed, and high precision autofocus operation with minimized noise. It has been fine-tuned for greater operability in manual-focus operation and includes a quick-shift focus system to provide an instant shift from auto to manual. An electromagnetic diaphragm control mechanism assures high precision exposure control and smooth focus tracking when used in combination with compatible digital SLR cameras and also enables the capture of video clips using automatic exposure control, even when there are considerable differences in brightness. It delivers exceptionally high resolving power and outstanding contrast even at open aperture, while capturing beautiful images with a smooth transition of the bokeh effect and a true-to-life depth of field.