Spanning a versatile zoom range and characterized by its bright design, the Tamron 17-70mm f/2.8 Di III-A VC RXD is a 25.5-105mm-equivalent lens for APS-C-format Sony E-mount mirrorless cameras. The wide to short-tele range is ideal for everyday shooting and the fast f/2.8 constant maximum aperture suits working in difficult lighting conditions and offers improved control over depth of field. Complementing this design is a series of specialized optics, including aspherical and low dispersion elements, that produce well-corrected imagery with high sharpness, 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.

Adding to the versatility of the zoom design is a Vibration Compensation image stabilization system, which reduces the appearance of camera shake for steadier photo and video recording in low-light conditions. Also benefitting handling, an RXD stepping motor enables quick, near-silent autofocus performance 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 zoom is designed for APS-C-format Sony E-mount mirrorless cameras and covers wide-angle to short-telephoto fields of view with its 25.5-105mm 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.
Two molded glass aspherical elements and one hybrid aspherical element help to correct distortion and spherical aberrations to achieve a high degree of sharpness and accurate rendering.
Two 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 1:4.8 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.
Rounded nine-blade diaphragm contributes to a pleasing bokeh quality.
VC image stabilization helps to minimize the appearance of camera shake for more effective handheld shooting in difficult lighting conditions.
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.