This large-aperture wideangle zoom hits the sweet spot for Sony full-frame mirrorless users, says Andy Westlake
This new optic maintains the same design philosophy, being a large-aperture zoom that achieves a compact size by employing a relatively modest focal-length range. Indeed its 1.6x zoom ratio is surprisingly short in a market where such lenses usually extend to 35mm. But there’s a good deal of sense in Tamron’s approach, as most users will surely be pairing the lens with a standard zoom starting at 24mm or 28mm.
The 17-28mm f/2.8 goes head-to-head in the market with the Sony Vario-Tessar T* FE 16-35mm F4 ZA OSS, and a spec comparison between the two makes for interesting reading. The lenses are the same length, but the Tamron is somewhat slimmer and 100g lighter, at 420g. The Sony has a wider zoom range but gathers a stop less light, and while it also includes optical stabilisation, this is inconsequential for users of cameras that include in-body IS – in other words, all except Sony’s first-generation full-frame mirrorless bodies. Crucially, the Tamron is more affordable, with a launch price of £900 compared to the Sony’s £1050 street price. So how does it perform?
Tamron 17-28mm F/2.8 Di III RXD – Features
Despite the lens’s relatively restricted zoom range, Tamron hasn’t skimped on the optics. The 13-element, 11-group design includes three aspherical elements, two low dispersion glass elements and an extra-low dispersion glass element, all with the aim of minimising distortion and chromatic aberration. Tamron also makes full use of in-camera software compensation to suppress residual aberrations.
Zooming and focusing are both internal, which means that the lens’s length and balance stay essentially the same at all times. The minimum focus distance ranges from 19cm at wideangle to 26cm at the 28mm setting, allowing striking close-ups. The barrel features moisture-resistant construction for shooting outdoors in challenging conditions, with fluorine coating on the front element to repel raindrops and fingerprints alike.
Filter uses will appreciate the 67mm thread, which is unusually small for a wideangle zoom, allowing the use of relatively inexpensive accessories. It’s also shared with both the Tamron 28-75mm f/2.8 and Sony’s compact 24-70mm f/4 standard zoom. A petal-shaped lens hood is included in the box and reverses neatly for storage, while the front element retracts further within the barrel on zooming to 28mm, providing additional shading against incident light.