With the large maximum aperture excellent background blur is possible even with a fast shutter speed the large maximum aperture makes excellent background blur possible even with a fast shutter speedthe aspherical lens element makes the lens compact and corrects spherical aberrations focal length and maximum aperture 28 mm 118 lens construction 10 elements in 9 groups diagonal angle of view 75 degrees focus adjustment rear focusing system with usm closest focusing distance 025m 08ft filter size