• In addition to 2 FLD glass and 2 SLD glass, 1 glass with a high refractive index and a high dispersion of abnormalities, this product thoroughly corrects chromatic aberration on axis. It also features two aspherical lenses to improve the resolution of the closest shooting distance • Bi-wire system eliminates mechanical connection of focus ring and focus drive Equipped with a newly developed coreless DC motor and controlled with algorithms to reduce operating noise and achieve excellent focus speed • The use of a super multilayer coat reduces flare and ghosting for high-contrast photography even in backlight conditions • Canon EF Mount