This is an essential standard lens for EOS family. This lens starts with the optical design concept of the FD 50mm f/1.4, which has always been highly regarded for its superior sharpness and color balance. Two high-refraction glass lens elements minimize flare at maximum aperture and eliminate astigmatism. Improvements in the quality of the focused image and a beautiful, natural blur of the background are realized. A micro USM (Ultrasonic Motor) provides fast, silent AF and full-time manual focusing. Color balance is virtually identical to the ISO recommended reference values.