Tamron 17-28mm f/2.8 Di III RXD Overview
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, and architectural shooting. Its bright f/2.8 constant maximum aperture complements this range and affords increased control over depth of field along with enhanced low-light performance. The optical design incorporates a both XLD and LD elements, which produce a highly corrected image with reduced chromatic aberrations and color fringing for improved clarity and color accuracy. Individual elements also feature Tamron’s BBAR coating, which suppresses flare and ghosting for greater contrast when working in backlit and harsh lighting conditions. Additionally, adding to the versatility, an RXD stepping motor enables quick, near-silent autofocus performance to suit stills and video, along with full-time manual focus override and 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 and smudging.Versatile wide-angle zoom is designed for full-frame Sony E-mount mirrorless cameras, however can also be used with APS-C models where it will provide a 25.5-42mm equivalent focal length range.Bright constant f/2.8 maximum aperture affords consistent brightness throughout the zoom range and offers improved control over depth of field.XLD (eXtra Low Dispersion) and LD (Low Dispersion) elements greatly reduce color fringing and chromatic aberrations throughout the zoom range in order to realize improved clarity and color accuracy.BBAR (Broad-Band Anti-Reflection) Coating has been applied to individual elements in order to suppress internal reflections, flare, and ghosting to achieve greater contrast and color fidelity when working in strong lighting conditions.RXD (Rapid eXtra-silent stepping Drive) autofocus motor delivers impressively quiet, quick, and smooth focusing performance to suit both stills and video applications. This focusing system also offers a minimum focusing distance of just 7.5″ and a 1:5.2 maximum magnification for working with close-up subjects. Full-time manual focus override is also possible and it is compatible with Sony’s Direct Manual Focus function or fine-tuned manual control.A moisture-resistant construction benefits this lens’ use in inclement conditions, and a fluorine coating has also been applied to the front lens element to protect against dust, dirt, and smearing.Rounded nine-blade diaphragm contributes to a pleasing bokeh quality.