Sigma AF 150mm F2.8 EX DG Apo Macro Lens for Canon

The first high speed, tele macro lens for Nikon digital and film SLR cameras -- shoot up to 1:1. The maximum lens aperture is F2.8. Two Special Low Dispersion (SLD) glass elements control various color aberrations and assure high image quality. A floating focusing system moves two different lens groups in the optical system to different positions. This system compensates for astigmatic aberration and spherical aberration. And, the high-speed motor (HSM) provides ultra quiet high-speed autofocusing as well as full-time manual focus override.