Sigma 12-24mm f/4 DG HSM | A

Maximum viewing angle 122 degrees aperture range f/4 to f/22 elements/groups 16/11 autofocus Ultrasonic (ring-type) Minimum focus distance 0.24m diaphragm blades 9 diameter x length 102x132mm weight 1150g price £1399/$1599

Unlike a fisheye or ‘curvilinear’ lens, this Sigma is a more conventional ‘rectilinear’ optic. As such, it aims to keep distortions to a minimum. Even so, the minimum focal length is tiny for an Fx-format lens, more like that of a Dx-format wide-angle zoom.

For a rectilinear lens, the Sigma’s maximum viewing angle is very impressive, at 122 degrees on the diagonal of the frame. That’s considerably wider than the 114 degrees of Nikon’s 14-24mm rectilinear wide-angle zoom, but a lot less than a fisheye lens.

One of the main upgrades in the latest ‘Art’ edition of this lens, compared with the previous Mk II version, is that it produces much less distortion. It’s not quite as ‘distortion-free’ as Sigma’s newer 14-24mm Art lens, but distortion is still remarkably low.

Measuring 102x132mm and weighing 1150g, the Sigma is over 50 per cent longer than the Nikon fisheye zoom, and more than twice as heavy. It’s also considerably bigger than the preceding Sigma 12-24mm Mk II lens.

If you want ultra-wide viewing angles without distortion, this Sigma has a lot to offer. It’s super-sharp in the central region of the frame and remains impressively sharp out to the corners. Colour fringing is minimal and image quality is top, along with quick autofocus.