Key Features EF-Mount Lens/Full-Frame Format Aperture Range: f/1.4 to f/22 Blue Spectrum Refractive Optics Element Two Aspherical Elements, One UD Element Subwavelength Coating Ring-Type Ultrasonic Motor AF System Full-Time Manual Focus Override Weather-Sealed Design, Fluorine Coating Rounded 9-Blade Diaphragm Show Less Characterized by its unique and advanced optical composition, 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