Canon's fixed length L-series lens with aspherical lenses and UD glass.Lens Construction: 13 elements in 10 groups Diagonal Angle of View: 84° Minimum aperture: f/22 Focus Adjustment: Rear focusing system with USM Closest Focusing Distance: 250mm Filter Size: 77mm Max. Diameter x Length, Weight: 3.4 in./86.9mm; 22.9 oz./650g Filter: 77mm Weight: 650g