The Canon EF 35mm f/1.4L II USM is a wide-angle L-series prime featuring a fast f/1.4 maximum aperture to suit working in difficult lighting conditions. Its optical design incorporates a Blue Spectrum Refractive Optics element; a specially developed element that helps to nearly eliminate chromatic aberrations and color fringing for notable clarity and color accuracy. Individual components also feature a Sub Wavelength Coating to suppress flare and ghosting for high contrast and color fidelity when working in harsh and backlit conditions. Its durable physical construction is dust- and moisture-sealed, and a fluorine coating has been added to the exposed elements to guard against fingerprints and smudging. Fast f/1.4 maximum aperture benefits working in low-light conditions and also affords significant control over the depth of field for working with selective focus techniques. A pair of aspherical elements and one UD element also help to control aberrations and distortions for sharper, more evident image quality. A ring-type Ultrasonic Motor (USM) is employed to deliver fast, precise, and quiet autofocus performance and full-time manual focus override. The rounded nine-blade diaphragm contributes to a pleasing out-of-focus quality that benefits the use of shallow depth of field and selective focus techniques.