Tamron 17-70mm F/2.8 Di III-A VC RXD for Sony APS-C cameras

Tamron has announced a premium standard zoom for Sony APS-C mirrorless cameras, with a uniquely useful combination of a 4.1x zoom range, constant f/2.8 maximum aperture and built-in optical stabilisation. The Tamron 17-70mm F/2.8 Di III-A VC RXD provides a 25.5-105mm equivalent range, and features a new dedicated processor to control the image stabilisation system and optimise its operation for different shooting situations.

The Tamron 17-70mm F/2.8 Di III-A VC RXD features the firm’s familiar cosmetic design

Optically the lens employs 16 elements in 12 groups, including two glass molded aspherical and one hybrid aspherical elements to maintain high resolution from centre to corner. Two low-dispersion glass elements are also included to suppress chromatic aberration. In addition, the lens supports in-camera corrections for distortion, chromatic aberration and vignetting.

Despite its extended zoom range, the 17-70mm is only fractionally larger than the firm’s 28-75mm F/2.8 Di III RXD for full-frame, showcasing a key advantage of the smaller APS-C sensor format. It measures 119.3mm in length and 74.6mm in diameter, weighs 525g, and employs 67mm filters. The barrel boasts moisture resistant construction, and a fluorine coating on the front element should help prevent fingerprints or raindrops spoiling your pictures.

Tamron has included seals to prevent dust and water getting into the lens

Tamron’s Rapid eXtra-silent stepping Drive (RXD) stepping motor is used for fast, silent autofocus, with minimum focus distances of 19cm at 17mm and 39cm at 70mm giving approximately 0.3x equivalent magnification. The lens is fully compatible with Sony’s advanced AF technologies, including Eye AF. Its firmware can be updated via the camera body.

Possibly the lens’s most intriguing new features is its optical stabilisation. The AI-trained Vibration Compensation system can distinguish whether the camera is being used on a tripod or hand-held, automatically detect panning movements, and adjust the stabilisation for recording video while walking. As a result, it does without the mode switches found on many other stabilised lenses.