Comprising a flexible wide-angle range, the 17-28mm f/2.8 Di III RXD from Tamron is a versatile zoom for full-frame Sony E-mount mirrorless cameras. Covering ultra-wide to wide focal lengths, this lens is particularly suitable for landscape, astrophotography, & architectural shooting. Its bright f/2.8 constant maximum aperture complements this range & affords increased control over depth of field along with enhanced low-light performance. The optical design incorporates a both XLD & LD elements, which produce a highly corrected image with reduced chromatic aberrations & color fringing for enhanced clarity & color accuracy. Individual elements also feature Tamron's BBAR coating, which suppresses flare & ghosting for greater contrast when working in backlit & harsh lighting conditions. in addition, adding to the versatility, an RXD stepping motor enables quick, near-silent autofocus performance to suit stills & video, along with full-time manual focus override & a minimum focusing distance of 7.5. Suiting this lens's use in inclement weather conditions, it also features a moisture-resistant construction along with a fluorine-coated front element to protect against fingerprints & smudging.