The Tamron 17-70mm f/2.8 Di III-A VC RXD Lens for Sony E maintains its large F2.8 maximum aperture throughout the entire zoom range (unlike variable aperture lenses that darken as you zoom). Thanks to F2.8 and high optical performance, 17-70mm F2.8 allows you to capture your subjects with clear details from wide-angle to telephoto. The three main advantages of a large F2.8 aperture are A) the ability to shoot successfully in lower light levels, B) beautiful and dreamy bokeh, and C) better control of depth-of-field which is particularly useful when intentionally limiting depth-of-field to improve portraits by blurring the area behind the main subject. Structurally, the optical formula includes 16 elements in 12 groups. It was created in pursuit of superior optical performance, utilizing an effective allocation of two GM (Glass Molded Aspherical) lens elements and one aspherical hybrid lens element. The optical design ensures high resolution and high contrast not just in the center of the frame but also in corners and at the edges.

This advanced lens focuses extremely close to a standard zoom lens for APS-C mirrorless cameras. The MOD (Minimum Object Distance) is just 0.19m (7.5 in) at the wide-angle end and 0.39m (15.4 in) at the telephoto end. When shooting very close to the subject, the lens enables expressive imagery with highly blurred backgrounds, a feature unique to large-aperture lenses. This allows you to create one-of-a-kind photos of a variety of subjects, from snapshots to portraits, landscapes, and even architectural photography. Close-up shots of scenery taken at the 17mm end maximize the unique perspective only true wide-angle lenses can deliver.

The AF drive on the Tamron 17-70mm f/2.8 Di III-A VC RXD Lens for Sony E includes an RXD motor unit to help you stay focused on the action. RXD uses an actuator to precisely control the rotational angle of the motor, allowing it to directly drive the focusing lens without passing through a reduction gear. A sensor that precisely detects the position of the lens enables high-speed and accurate AF, which is ideal when shooting continually moving subjects or recording video. With a focusing system that is both smooth and quiet, the 17-70mm F2.8 lets you shoot free from stress not worrying about the drive sound in a quiet environment.