Zuiko 825mm f4 Pro weatherproof, filter ring, compact, focus clutch super wide zoom. Features. Micro Four Thirds System. 1650mm 35mm Equivalent. Aperture Range f/4 to f/22. 2 Aspherical ED 1 Super ED ElementsSpecifications. Format Compatibility Micro Four Thirds. Angle of View 107 to 47. Optical Design 16 Elements in 10 Groups. Diaphragm Blades 7, Rounded. Focus Type Autofocus. Image Stabilization Yes. Filter Size 72 mm Front. Dimensions 3 x 3.5. Weight 1.5 lbs