The lens is constructed from 16 elements including 3 Glass-Molded aspheric lenses and two UD lenses. The aspheric lenses significantly reduce any distortion, so that details in the peripheral area look just as good as the subject in the middle. Two UD lenses also minimize chromatic difference, preserving more realistic color tones. A 9-blade circular aperture also brings up the image quality by providing almost-round shapes when shooting with a bokeh effect.
As this lens belongs in the prestigious L series of lenses, it has been produced with extremely high durability and toughness for reliable usage. The lens mount, switch panel, zoom ring and focusing ring have all been constructed with a dust-proof and drip-proof structure, allowing it to be used in harsh conditions. The surface of the lens elements have been coated with fluorine, which easily repels water and oil so that they can be easily wiped off with a dry cloth.