Ideal for portrait, still life, or low light photography, the Pentax DA 55mm F1.4 SDM lens assures outstanding image quality with clear, high-contrast images, even at image field edges thanks to super-low-dispersion optical elements, extra-low dispersion (ED) optical elements and Pentax original lens coatings. It features water and dust resistant sealing for reliable operation in inclement conditions, and the Pentax quick-shift focus system to allow instant auto-to-manual focus switching. The objective lens surface is treated with Pentax original Super Protect (SP) coating. This special fluorine compound is applied through a vapor deposition process to create a surface that effectively repels dust, water and grease. The combination of special lens coatings, ideal curvature and best positioning of optical elements assures optimized digital imaging characteristics, while effectively minimizing flare/ghosting. It also features an aero bright coating for maximum light transmission, and rounded diaphragm blades to create a more circular aperture for smooth, beautiful bokeh at large apertures. The advanced SDM mechanism assures extra-smooth, super-quiet autofocus operation using a supersonic motor installed in the lens body. Thanks to its SDM-exclusive autofocus system, the lens is quite compact, despite its large maximum aperture.