Tamron 20-40mm F/2.8 Di III VXD

Andy Westlake tests a large-aperture zoom for Sony full-frame cameras with an unusual focal-length range

- Andy Westlake

On the whole, lenses tend to fit into a few clear categories: wideangle zoom, standard zoom, and so on. But the Tamron 20-40mm F/2.8 Di III VXD is a little different. Designed for Sony full-frame mirrorless cameras, it’s one of a recent spate of lenses that start at 20mm – wider than most standard zooms, but narrower than other wideangle zooms – and then extend into ‘standard’ territory. But in contrast to the Panasonic Lumix S 20-60mm F3.5-5.6 and the Sony FE 20-70mm F4 G, it provides an f/2.8 maximum aperture, albeit with a short 2x zoom range. It really is one of a kind.

This does beg the question, though, of who and what the lens is for? Photographers adding a wideangle zoom to their existing kit will likely be tempted to get something wider, such as the Tamron 17-28mm F/2.8 Di III RXD or the Sigma 16-28mm F2.8 DG DN. But the clue comes from Tamron’s preferred designation of the 20-40mm as a ‘standard’ lens. For certain purposes, such as landscape and travel photography or vlogging, that wide-to-standard range means some users might keep it on their cameras most of the time.

Other key attractions of the Tamron 20-40mm f/2.8 lie with portability and affordability. It’s one of the smallest Sony E-mount full-frame zooms you can buy; only the Sony FE 28-60mm F4-5.6 kit zoom is both smaller and lighter. At £879, it’s also quite keenly priced for an f/2.8 zoom. So how does it perform?

Features