Photography News Issue 43

Photography News | Issue 42 | absolutephoto.com

AwardWinner - First tests

Sigma 12-24mmf/4DGHSMArt £1399 open, improving to excellent at f/5, and tailing off a little thereafter. This was repeated when shooting at 18mm and at 24mm. Results from the smaller apertures were best towards 24mm.

Specs

If you want to shoot wide-angle on a full-frame Canon or Nikon DSLR there are lots of options. One of the latest is Sigma’s 12-24mm f/4 DG HSM Art, which also happens to be the winner of this year’s Wide-Angle Zoom category in our Awards. The lens can be used on APS-C DSLRs, too, but you’ll be getting an effective focal length of 18-36mm on Nikon and 19-38mmon CanonDSLRs. The 12-24mm f/4 DG HSM Art is a competitortoCanon’s11-24mmf/4Land Nikon’s 14-24mm f/2.8. The ultra wide- angle 12-24mm focal length is right at home with landscapes, architecture, or cramped interiors, and its constant f/4 aperture lends it to low light. There’s very little to deal with on the lensbarrelitself,justthezoomandfocus rings, an AF/MF switch and distance window. The zoom ring is quite narrow, but falls easily to hand when cradling the lens and its surface is well grooved, so there’s lots of grip, even when wearing gloves or if the surface is a little slickwith rain or spray. As you’d expect for a 2x zoom, the turn is short, but it’ll still take more than a single rotation to go from near to far; or two turns if you have smaller hands. There’s a good level of resistance in the zoom though, and nothing feels slack in its operation. The focus ring is mounted at the front and is larger in diameter, as it sits around the projection of the front element. It has the same grooved feel as the zoom ring, and a light, accurate action, with no slip. The throw is long, which made manually focusing easier; especially important if you’re shooting starry skies. The AF/MF switch sits easily under your thumb; it’s a bit stiff, so at least youknowit’s not going to slip. The barrel, a mix of metal and Thermally Stable Composite (TSC), has averysolidfeel.Theconstructionisdust and splash proof, with seals to protect from dust and rain, and the front and rear glass has a water- and oil-repellent coating. This is important at the front, as the lens uses a built-in lens hood, and therefore a screw-in protective filter can’t be used (a customholder like Lee Filters’ SW150 will be required). In comparison, the (admittedly more expensive) Canon 11-24mm has a slot for a gel filter in rear. In zooming, the front element extends by about 1cm, but while it’s in theory possible that this could strike a close-up subject, it’s not all that likely. Testing the 12-24mmArt on a Canon 5D Mark IV, autofocus performance wasn’t the fastest, but it was assured. In fairness, most of this lens’s subjects won’t rely on lightning-fast lock-on and the Hyper Sonic Motor (HSM) means it’s silent and smooth. Minimum focus is 24cm at the long end, and only fractionallymore at thewidest, which is veryuseful for enlarging small subjects, ormaking themost of foreground. When it comes to image quality the 12-24mm performed well, with some drawbacks.Testingsharpness,Ifocused using live view on flat subjects and ran the lens through its aperture range. In terms of edge-to-edge sharpness, at the 12mm end, the lens performed best at f/11, before dropping off at f/16 and beyond. That said, centre performance was very good when shooting wide

Price

£1399

Format Full-frame and APS-C Mount Canon, Nikon and Sigma Construction 16 elements in 11 groups Special lens elements ELD (Extraordinary Low

The 12-24mm f/4 DG HSM Art features a moulded glass aspherical lens, that claims to minimize distortion, spherical aberration, and coma flare. This proved true, with the exception of fringing, which was most noticeable at 12mm, where there was obvious magenta/green in the corners, at all apertures. Fringing was much reduced by 18mm, andgone at 24mm. The centre of the imagewas free of it throughout. Vignetting is well controlled. It was most noticeable at the 12mm setting when shooting wide open, but is only minor and quickly disappears as you approach the middle apertures. Distortions were also well marshalled; there’s some minor barrelling at 12mm, but it’s fractional and a very good performance for a lens this wide. KS

Dispersion), SLD (Special Low Dispersion) and FLD (“F” Low Dispersion) Coatings Super Multi-Layer Coating Filter size N/A Aperture range f/4-f/22 Diaphragm 9 blade, rounded diaphragm Internal zoom No Internal focus Yes

Minimum focus 24cm (at 24mm) Focus limiter Max. magnification 1:4.9 Distance scale Yes Depth-of-field scale No Image stabiliser No Tripod collar No Lens hood Yes, integral Weather-sealed Yes (moisture and dust) Dimensions (lxd) 102x131.5mm Weight 1150g Contact Sigma-imaging-uk.com

12mm

18mm

12mm

F/4

F/5.6

F/8

Left We composed against flat subjects in order to assess image sharpness from the centre to the edge. Pictures were taken throughout the 12-24mmArt’s aperture range and overall image quality was very good.

F/11

Verdict

At £1399, the Sigma 12-24mm f/4 DG HSM Art is more affordable than both Nikon and Canon’s ultra wide-angle zooms. It performs well in the sharpness stakes, especially wide open in the centre, and while it does suffer fringing at its widest end, this falls off quickly. Distortion, vignetting and flare are well controlled throughout.

F/16

F/22

Pros Well built with good handling, image quality is generally very good Cons Some fringing at the widest settings