Vivitar's 35mm f/1.4 Aspherical Lens for Pentax K is a very fast professional-quality wide-angle lens for Pentax K mount cameras. This manual focus, manual exposure lens has been constructed using hybrid aspherical lenses and multi-layer coatings, to produce sharp images with a minimum of flare and/or ghosting. Using the fast f/1.4 aperture allows you to make images in low-light situations without resorting to noise-inducing high ISO settings; and the wide aperture also produces subject/background separation, as well as impressive bokeh (the out-of-focus portion of a photograph).
This lens also works very well when shooting video with a DSLR--the iris (aperture) is controlled by a large, rubber-clad manual-focus ring with a damped turning action. Its long turning radius is great for precision focusing and cinematically smooth focus pulls.