The Sigma 70-200mm f/2.8 DG OS HSM Sports Lens is a flexible telephoto zoom characterized by its bright and sophisticated design. The fast constant f/2.8 maximum aperture excels in difficult lighting conditions and also offers increased control over depth of field for isolating subjects. In regard to the optical layout, an impressive 10 low dispersion elements are used to greatly reduce chromatic aberrations and color fringing for improved clarity and color accuracy.