The Samyang 16mm f/2.0 ED AS UMC CS Lens for Pentax is a manual focus, wide-angle lens compatible with APS-C format DSLR digital cameras. It provides an 83.1deg. angle of view which translates into a 35mm format equivalency of 24mm. Its fast maximum aperture of f/2.0 is effective in low light shooting and provides shallow depth of field. With two aspherical lens elements and one extra-low dispersion element, chromatic aberrations are minimized and sharp, color-accurate images are the result. UMC lens coating facilitates even light transmission and reduces ghosting and flare.