The ef 24 70 mm f4l is usm is the perfect zoom to complement full frame dslrs like the eos 6d with 2 aspheric and 2 ud elements the ef 24 70 mm f4l is usm delivers high quality images with excellent detail throughout the entire zoom range a 9 blade circular diaphragm delivers beautiful soft backgrounds it offers a minimum focusing distance of 125 feet across the entire zoom range and has a macro mode at the telephoto end with up to 07x magnification and is easily accessible with a one