The fastest wide angle L lens in its class with excellent definition. The first EF lens uses a ground and polished aspherical glass lens element and a UD (Ultra-low Dispersion) glass lens element simultaneously, in order to achieve a large f/1.4 aperture and superb optical performance of a L lens at the same time. The floating optical system provides high image quality over the entire focusing range. This is the first L lens with lens elements, made of only ecologically sound lead-free glass. A ring USM (Ultrasonic Motor) and rear focus system offer silent, high-speed AF. A full-time manual focusing and a non-rotating filter frame provide excellent operability. A petal-shaped lens hood comes with the lens.