Conclusion

The new Tamron 28-200mm F2.8-5.6 Di III RXD is everything that its main rival, the Sony FE 24-240mm f/3.5-6.3 OSS, should have been, offering a compellingly versatile, high-performing package that makes it the best all-round lens that we've ever tested.

The ability to shoot at f/2.8 on an all-in-one zoom like this is unheard of, but not that its only available at 28-31mm focal lengths, whereupon to changes to f/3.1. Still, the ability to shoot at 28mm at f/2.8 and focus as closely as 19cm shouldn't be underestimated.

It delivers excellent levels of sharpness in the centre of the frame throughout its zoom range, even performing well both wide-open and at the longer telephoto focal lengths, although you'll need to stop down quite a lot to get similar quality at the edges.

There's some vignetting and distortion at both ends of the zoom range when shooting in the RAW format. The Sony A7-series cameras automatically correct this for JPEG files, but as a lot of owners will no doubt be relying on RAW to deliver optimum quality, it does require some post-processing to remove it.

Bokeh is pretty nice for such an all-purpose zoom, especially when shooting at 200mm, while chromatic aberrations are largely well controlled.

The lens is prone to flare when shooting directly into the sun and the sunstars aren't particularly good even at f/16, but as noted above it can usefully focus as close as 19cm at the 28mm focal length.

The RXD auto-focusing system proved to be reliably quick, accurate and quiet on the Sony A7 III that we tested the lens with, and it's also fully compatible with all of Sony's focusing modes.

Build quality is good rather than excellent. It's not quite at the same level as the metal construction of Tamron's SP lenses or the better Sony zooms, but the polycarbonate construction does at least ensure that the lens is very light. It's also usefully weather resistant too, with leak-resistant seals employed throughout the lens barrel.

The main drawback of this lens from a feature point of view is the lack of any built-in vibration compensation, with the lens instead relying on the Sony camera body, something that won't be an issue unless you own a first generation Alpha model.

Compared to its main rival, the Sony FE 24-240mm f/3.5-6.3 OSS, the Tamron 28-200mm is much cheaper, especially in the UK where it's around £200 less than the Sony alternative.

If you want an all-purpose lens that covers most focal lengths and subjects, then the Tamron 28-200mm F2.8-5.6 Di III RXD is easily the best choice for Sony shooters. Highly recommended!

Ratings (out of 5)
Design	4.5
Features	4
Ease-of-use	4.5
Image quality	4.5
Value for money	4