Optimized image quality for Digital SLR cameras. Floating Internal Focusing (FIF) system minimizes the aberration in entire focusing range. Super Multi Layer (SML) coating reduces the ghost caused by reflections from the surface of digital image sensors. Minimum aperture of F/45 provides greater depth of field (F45 for Sigma, Canon & Konica Minolta mounts & F32 for Nikon & Pentax mounts). A screw-in hood for convenient use of circular polarizing filters