This Sigma ‘DN’ lens is designed exclusively for mirrorless full-frame cameras, and is available in Sony E and Leica L mount options, the latter suiting both Sigma and Panasonic bodies as well as Leica cameras. It has a real retro charm, with a metal barrel and hood, and even a magnetic front lens cap which is supplied in addition to the more regular plastic one. There’s an AF/MF focus mode switch and two control rings, dedicated to manual focus and aperture control. The latter rotates in one-third f/stop steps, with no de-click option. As with the Canon lens on test, that’s only a concern when shooting video, and no problem for street stills.
Build quality feels very robust and the lens features a rubber weather-seal gasket on its metal mounting plate, although no weather-seals are added around other joints. Despite its metal construction, the Sigma is only slightly heavier than the Canon lens, at 325g, and noticeably lighter than the Nikon. The aperture rating of f/2 is a third of a stop slower than that of the Canon and Nikon lenses, but the Sigma is a full f/stop faster than the Tamron.