The 17-28mm zoom’s optical design consists of 13 lenses in 11 groups, including three aspherical lens elements, two LD (Low Dispersion) lens elements and one XLD (eXtra Low Dispersion) lens element that has properties close to those of fluorite. Together they efficiently suppress chromatic and other aberrations. Additionally, Tamron’s legendary BBAR (Broad-Brand Anti-Reflection) Coating effectively reduces ghosting and flare. Leveraging camera functions*, it provides excellent optical performance matching the latest high resolution image sensors from edge-to-edge throughout the entire zoom range. The combination of compact size and light weight plus high resolution performance lets users capture a wide variety of genre including landscapes, architecture and street photography.
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.