The smc PENTAX-DA 16-50mm f/2.8 ED AL[IF]SDM wide angle zoom lens delivers the highest level of optical quality and includes SDM technology for fast, accurate, quiet focus. Bringing together advanced optical technologies, including aspherical elements, special optical-glass elements and original lens coatings, these new interchangeable lenses are superior to any existing lens series in terms of contrast, clarity and edge-to-edge sharpness. more info