SIGMA 24-70MM F/2.8 DG DN ART

A classy zoom for Sony E-mount and Panasonic, Leica and Sigma L-mount cameras

Anybody with a Sony or Panasonic full-frame mirrorless camera will be naturally drawn to the own-brand FE 24-70mm f/2.8 G Master (£1,799/$1,998) or Lumix S PRO 24-70mm f/2.8 (£2,149/$2,198), respectively. Both are fine lenses but come with fairly hefty price tags. At around half the price in most regions, the smart money is on this Sigma Art-line alternative.

Sigma already had a strong contender in the DSLR market, with its optically stabilised 2470mm DG OS HSM Art lens for Canon and Nikon cameras, competing with the Tamron lens on test. The ‘DN’ edition for mirrorless cameras ditches the optical stabiliser, relying on in-body stabilisation to keep things steady. In other areas, there are some significant improvements.

Optical finery includes six top-grade FLD (‘Fluorite’ Low Dispersion) elements, plus two

SLD (Special Low Dispersion) elements, and three aspherical elements. Along with Sigma’s proprietary Super Multi-Layer Coating, the DN lens has Nano Porous Coating to further reduce ghosting and flare. The diaphragm blade count goes up from nine to 11, ensuring the aperture remains well-rounded when stopping down and enhancing bokeh. As with the Canon and

Nikon lenses, autofocus is driven by a stepping motor and comes with the typical ‘fly-by-wire’ manual focus ring. There’s no focus distance scale and it lacks a digital display.

High-end construction includes extensive weather-seals, as fitted in the other lenses on test. Controls include a zoom lock switch, AF/MF switch and an AF-L (autofocus lock) button, which can be customised to carry out different functions, depending on camera type and model, although there’s no additional, customisable control ring, as in the Canon and Nikon lenses.

Autofocus is fast and virtually silent, while manual override operates with smooth precision. Excellent centre-sharpness is on a par with the Canon lens, along with a similar wide-aperture drop-off towards the edges and corners. Barrel distortion at 24mm is more noticeable than with any other lens in the group and vignetting is quite pronounced at f/2.8, however, automatic in-camera corrections are available.

BUILD QUALITY CONTROL RINGS FUNCTION SWITCHES THE WEATHER-SEALED CONSTRUCTION IS OF HIGH QUALITY, BUT THE LENS IS ABOUT 200G LIGHTER THAN SIGMA’S ‘DG’ ART VERSION FOR DSLRS AND MORE IN KEEPING WITH SLIMLINE MIRRORLESS CAMERAS. LIKE THE CANON AND NIKON LENSES, THE SIGMA HAS A REARWARD ZOOM RING AND FORWARD, ELECTRONICALLYCOUPLED FOCUS RING, BUT THIS TIME WITH NO ADDITIONAL, CUSTOMISABLE CONTROL RING. AS WELL AS A ZOOM LOCK SWITCH, WHICH OPERATES AT 24MM, THERE’S AN AF/MF FOCUS SWITCH AND A CUSTOMISABLE AF-L (AUTOFOCUS-LOCK) PUSH BUTTON.