LENS TEST
Andy Westlake assesses a compact, affordable, large-aperture wideangle zoom for APS-C cameras
I’ve been reviewing lenses for over 16 years now, so it’s not often that I’m surprised when a new optic shows up for testing. But the Sigma 10-18mm F2.8 DC DN is an exception. It’s an ultrawideangle zoom for APS-C mirrorless cameras with a bright maximum aperture, and it’s tiny.
In fact, it measures just 62mm long and weighs only 260g.
What’s more, at £649, it’s one of the most affordable lenses of its type. It’s available for Fujifilm X, Sony E, and L-mount cameras.
To put these diminutive dimensions into context, we just have to look at other autofocus ultra-wide zooms available in these mounts. Perhaps its closest competitor is the Tamron 11-20mm F/2.8 Di III-A RXD, which is 24mm longer, 75g heavier, and costs £50 more. This Sigma 10-18mm f/2.8 is also considerably smaller than Fujifilm’s XF 10-24mm F4 R OIS WR, which retails for £949. Only the Sony E PZ 10-20mm F4 G is smaller and lighter, but it’s a stop slower and you can expect to pay £100 more for it.
Further perspective is provided by the older Sigma 10-20mm F3.5 EX DC HSM for APS-C DSLRs. This lens was 26mm longer and precisely double the weight, despite gathering two-thirds of a stop less light. This portability makes the Sigma 10-18mm f/2.8 an extremely tempting proposition, but is it all just a bit too good to be true?
Features
With its 10-18mm range, this lens provides an ultra-wideangle view that’s equivalent to using a 15-27mm lens on full-frame. As a result, it should be attractive to photographers shooting subjects such as landscapes, architecture, and interiors. Its f/2.8 maximum aperture should also make it handy for low-light photography. However, there’s no optical stabilisation on board.
Looking at the optical design, Sigma has employed 13 elements in 10 groups. This includes 4 aspherical elements to maintain sharpness from corner to corner, along with 1 element crafted from super-low dispersion glass and 3 from ‘F’ low dispersion glass, which together suppress colour fringing. The firm is entirely open that it employs a mix of optical and software corrections to deliver geometrically correct images, in which straight lines at the edges of the image are rendered as such, and not curved.
Autofocus is driven by a stepping motor, promising fast, quiet and accurate focusing. The minimum focus distance is just 11.6cm at the widest zoom setting, which equates to 0.25x magnification
