Construction: 10 elements in 7 groups (inc. 2 asph. element & 3 ab normal disp. element) Focal Length: f = 14mm (21mm 35MM equiv.) AOV 89° Max Aperture: F2.8 Min Aperture: F22 Aperture Blades/Stop Size: 7 (rounded diaphragm opening) 1/3 EV (19 stops) Focus Range: 18cm - infinity Max Magnification: 0.13x Filter Size: 58mm