Irix 11mm f/4

From £543/$678 www.irixlens.com

Fresh from the success of its 15mm f/2.4 (which won a Great Value award in issue 70’s Big Test of wide-angle primes) – lens newcomer Irix is going wider with its follow-up offering. Like the 15mm, this lens is available in two flavours: Firefly and Blackstone. The differences are purely external: the latter boasts a premium aluminium-magnesium alloy barrel, while the cheaper Firefly version is encased by a plastic barrel to keep weight down to 730g. Both options contain the same optical elements, which include four high-refractive elements, two ED elements and three aspherical lenses.

We’ve had some hands-on time with the Blackstone version of the lens and first impressions are positive. Its lens barrel feels reassuringly solid, though it is fronted by a fixed petal hood made from plastic, presumably to help reduce weight.

The wide focus ring is well weighted, with a long, smooth travel, so it’s easy to make fine focus adjustments – useful, as the lens lacks autofocus, though aperture information is transmitted to your Nikon to enable automatic exposure metering. A narrower ring at the front of the barrel will lock the focus ring, and while effective, the tapering hood forces your fingers towards the focusing ring, making it all too easy to inadvertently change focus while trying to lock it.

Our initial lab testing reveals superb centre-frame sharpness up to f/8, although edge sharpness does fall off noticeably at all apertures. Distortion is apparent when shooting geometric subjects at very close range, but it’s otherwise negligible. You will notice some fringing at the edges of the frame, but Sigma’s similarly priced 12-24mm f/4.5-5.6 II DG HSM produces more aberrations at 12mm.

First impressions_ Lenses this wide with FX coverage are rare, and initial impressions suggest it offers sound performance.