A highly practical medium telephoto lens with superb delineation and portability. Images are sharp and clear at all apertures. Through computer simulations, the lens has been designed to give beautiful background blur. Since the front lens group does not rotate during focusing special filter effects are not affected. Designed to give beautiful background blur 85mm focal length 1:1.8 maximum aperture 28° 30' diagonal angle of view 0.85m / 2.8 ft closest focusing distance Focal Length & Maximum Aperture- 85mm 1:1.8 Lens Construction- 9 elements in 7 groups Diagonal Angle of View- 28° 30' Focus Adjustment- Rear focusing system with USM Closest Focusing Distance 0.85m / 2.8 ft Filter Size- 58mm Max. Diameter x Length, Weight 3.0" x 2.8", 15.0 oz. / 75.0 x 71.5mm, 425g