The 50mm f/1.4 standard lens is a terrific choice for both casual and professional photographers. The lens is outfitted with two high-refraction lens elements and new Gaussian optics, which combine to eliminate astigmatism and suppress astigmatic difference. As a result, the lens obtains crisp images with little flare even at the maximum aperture. The lens's f/1.4 speed, meanwhile, is perfect for available-light shooting. And as a bonus, this lens is the only lens in the EF system to offer an extra-small Micro Ultra Sonic Motor (USM) while still providing a full-time manual focusing option. Other features include a close focusing distance of 1.5 feet, a 58mm filter size, and a one-year warranty.