Ultra-wide zoom performance with a constant f/2.8 aperture, three aspherical and four ED elements, plus ARNEO and Nano Crystal Coatings defines this Z-mount lens. A stepping motor drives fast, silent autofocus for stills and video, and full weather sealing guards against the elements. It’s best for landscape and architectural photographers who require 14mm edge-to-edge sharpness and flare resistance in harsh light.