Verdict

The Sigma 18-50mm f2.8 DC DN is the zoom many cropped mirrorless cameras have been waiting for: the range may be fairly standard, but the constant f2.8 aperture and corner sharpness are a step-up over basic kit zooms, and crucially it won’t break the bank or your back either.

In a market dominated by full-frame, it’s a very welcome addition to the often neglected APSC format and on the whole does a good job: sharper and brighter than typical kit zooms with a greater opportunity for shallower depth of field effects. Sure you need to stop down a little for the best corner sharpness and it would have been nice to have weather-sealing beyond the mount, but in both respects it’s still probably better than what was supplied with your APSC camera, especially if you’re one of the many owners of Sony’s 16-50mm.

The real downsides are a lack of optical stabilisation, an omission that will frustrate owners of the many APSC bodies lacking IBIS of their own, and a range that would have been more compelling had it started at 16 rather than 18mm. It’s two main rivals address some of this: Sony’s 16-55 2.8 extends the range at both ends and delivers the best results, but lacks IS, while Tamron’s 17-70 2.8 starts a tad wider, ends almost 50% longer and includes optical stabilisation. But both models are larger, roughly double the weight and more expensive too: $799 for the Tamron and a whopping $1399 for the Sony. 

Indeed at the asking price of $599, it seems almost churlish to complain about the Sigma’s shortcomings, other than the sheer cruelty of not announcing a version for Canon’s much-neglected EF-M mount. But if you own one of the many Sony A5000 or A6000 bodies and despair at the 16-50 kit zoom, salvation has arrived.