Conclusion

The days of third-party lens manufacturers just making generic, budget copies of the marquee brands are long gone, and the new Sigma 28-105mm F2.8 DG DN Art for E-mount and L-Mount cameras is most certainly a case in point.

This is the only standard zoom lens currently on the market to offer such a versatile focal range paired with a constant f/2.8 aperture in a relatively compact package, making it almost perfect as an all-in-one event lens for both stills and video.

Some users may lament the lack of 24mm reach rather than 28mm, whilst others may bemoan the near 1kg weight, but Sigma have inevitably had to make compromises somewhere in order to create such a versatile and fast zoom.

The main alternatives to this lens are either 24-105mm f/4 or 24-70mm f/2.8 offerings, or the 35-150mm F2-2.8 lenses from Tamron and Samyang. None of them offer quite the same combination of wide-angle to telephoto focal lengths and fast apertures as this new Sigma 28-105mm f/2.8.

In terms of its optical performance, it's acceptably sharp wide-open at f/2.8 in the centre throughout most of the zoom range and almost as good at the edges of the frame. It also produces some very nice bokeh effects thanks to the 12-blade iris diaphragm and fast maximum aperture.

There is some very obvious vignetting at wide-open apertures, but barrel distortion at 24mm and pincushioning at 105mm are well-controlled, as are chromatic aberrations, whilst the close focus ability is a great addition.

As well as very good image quality, the auto-focus system incorporates the very latest linear motor HLA (High-response Linear Actuator). This lens features fast, near-silent, reliable auto-focusing on the Panasonic Lumix S5II camera that we tested it with, with the Click and Lock switches for the aperture ring making it well-suited to both stills and movies.

It offers a high level of build quality, plus it's usefully dust and moisture resistant too, although not fully water-proof, and Sigma have also included a very good lockable lens hood and padded case in the overall package. 

It may not be the sharpest or lightest standard zoom lens on the block, but for many users the as-yet unique combination of 28-105mm focal range and f/2.8 maximum aperture will no doubt prove to be very tempting indeed, and justifiably so.

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