Lumix S Pro camera lens - 16-35mm wide angle zoom l-mount lens for Lumix S Series full-frame digital Mirrorless cameras. Video support - excels in video recording performance with a mechanism to suppress focus breathing and micro-step aperture control for smooth exposure change. Lens elements - 12 elements in 9 groups, the use of 3 aspherical lenses, An ED (extra-low dispersion) lens and a UHR (ultra-high refractive Index) lens with optimum alignment to achieve high mtf performance. Rugged lens design - dust/splash*/freeze-resistant design withstands use under harsh conditions for high mobility. Focus Clutch Mechanism - enables instant AF/MF switching, accurate manual focusing and suppressed focus breathing