Pentax SMC 15mm f/4.0 DA ED AL Limited Wide Angle Lens for Pentax Digital SLR Cameras Compact wide angle limited lens. High-grade aluminum construction of the lens barrel, hood, and cap. Quick-shift Focus System for instant switching from auto to manual focus. PENTAX SP coating protects the exposed lens elements. Extra low Dispersion glass and a hybrid aspherical lens element improve contrast and clarity