Zoom lens with constant length design and construction, where the lens does not extend along the zoom, providing a more comfortable and secure zoom operation. High speed autofocus and high precision system: approx. 0.015 sec. Built with 11 elements in 9 groups including 3 aspherical and 3 ED lenses, which suppresses chromatic aberrations and maintains high resolution throughout the zoom range. Lens with 13 sealing points allowing it to be resistant to inclement weather and up to 10 degrees below zero. It covers a versatile focal length range, from a 16mm wide angle (24mm equivalent in 35mm format) that excels in landscape photography and group shots, to a medium telephoto lens of 50mm. (76mm equivalent in 35mm format) ideal for portrait photography.