Standard focal length 50 millimeter lens is effective in a multitude of shooting situations and ideal for day-to-day shooting | Elements/Groups: 7/6, Diaphragm: Blades 8, Filter Thread: Font 58 millimeter. Minimum focusing distance: 17.8 inch | An f/1.4 maximum aperture provides clear imaging in low light situations and shallow depth of field | Ultrasonic autofocus motor (USM) operation is fast, smooth and virtually silent | 2 high-refraction lens elements and new Gaussian optics eliminate astigmatism and suppress astigmatic difference | This large aperture standard prime lens has superior peripheral brightness even at the maximum aperture | Lens Construction: 8 elements in 6 groups, Filter Size: 77mm | Optimized for Digital, super multi-layer coating minimizes flare and ghosting, a common problem of digital Cameras | The optimum optical design and molded glass aspherical lens elements provide excellent correction for all types of aberrations, including coma aberration, resulting in superior optical performance | The Hypersonic Motor (HSM) ensures silent, high speed auto-focusing as well as full time manual focusing capability | This large aperture standard prime lens has superior peripheral brightness even at the maximum aperture | Lens construction: 8 elements in 6 groups, Filter size: 77mm | Optimized for Digital – super multi-layer coating minimizes flare and ghosting – a common problem of digital cameras | The optimum optical design and molded glass aspherical lens elements provide excellent correction for all types of aberrations, including coma aberration, resulting in superior optical performance | The Hypersonic Motor (HSM) ensures silent, high speed auto-focusing as well as full time manual focusing capability