Focal Length & Maximum Aperture 28mm 1:1.8 Lens Construction 10 elements in 9 groups Diagonal Angle of View 75° Focus Adjustment Rear focusing system with USM Closest Focusing Distance 0.25m / 0.8 ft. Filter Size 58mm Max. Diameter x Length, Weight 2.9" x 2.2", 10.9 oz. / 73.6 x 55.6mm, 310g