Conclusion

The new Sigma 24-105mm F4 DG OS HSM offers a versatile focal range whilst being tack-sharp from 24mm to 80mm, particularly in the centre of the frame. Sharpness at 105mm isn't quite as good, or at the edges of the frame throught the zoom range, but overall the Sigma 24-105mm F4 DG OS HSM is one sharp lens. Vignetting at wide-open apertures, chromatic aberrations at the edges of the frame, and some barrel distortion at 24mm are the only other real optical issues of note, something that similar lenses from other manufacturers also tend to suffer from.

Build quality is excellent, with the brass lens mount and sober all-black design adding to the high-quality feel, and Sigma have even generously included a very good lens hood and padded case. It is a little heavier than its main rivals though. Focusing was very quick on the Canon EOS 5D Mark III that we tested the lens with, and manual focus over-ride at any time is a great feature, as is the effective built-in optical image stabilisation system.

Even the price of the Sigma 24-105mm F4 DG OS HSM is attractive, undercutting the rival lenses from Canon and Nikon (Sony don't currently offer an equivalent zoom lens). We can strongly recommend the new Sigma 24-105mm F4 DG OS HSM as a well-built standard zoom lens that delivers superb results on the latest full-frame cameras.

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