Standard lens featuring superb quality and portability. Two high-refraction lens elements and new Gaussian optics eliminate astigmatism and suppress astigmatic difference. Crisp images with little flare are obtained even at the maximum aperture. Two high-refraction lens elements 50mm focal length 1:1.4 maximum aperture 46° diagonal angle of view 0.45m / 1.5 ft. closest focusing distance. Focal Length & Maximum Aperture- 50mm 1:1.4 Lens Construction- 7 elements in 6 groups Diagonal Angle of View- 46° Focus Adjustment- Overall linear extension system with USM Closest Focusing Distance-0.45m / 1.5 ft. Filter Size- 58mm Max. Diameter x Length, Weight 2.9" x 2.0", 10.2 oz. / 73.8 x 50.5mm, 290g