SIGMA 50MM F/1.4 DG HSM ART
Something of a modern classic among 50mm primes, this Sigma fulfils its arty aspirations
Originally designed with Canon and Nikon DSLRs in mind, the Sigma 50mm is typical of Sigma’s Art lineup in that it is big and hefty, and goes all-out for image quality and artistic expression. There have certainly been no compromises here in terms of keeping the size and weight down and, as such, it is relatively huge compared with Canon’s EF and Nikon’s F-mount 50mm f/1.4 primes. It also weighs in at 815g, making it far heavier than any other lens in this test group.
Building on its popularity within DSLR circles, the lens has also been re-purposed for mirrorless cameras, with Leica L and Sony FE becoming available. There is even an A-mount version for Sony’s ‘SLT’ translucent-mirror bodies such as the fullframe A99 and crop-sensor A77.
However, unlike Sigma’s ‘DN’ range of lenses, the 50mm ‘DG’ only has an adapted mount and electronics for compatibility with mirrorless cameras, rather than being redesigned from scratch. Compared with Sigma’s pre-Global Vision 50mm f/1.4 prime, most of the Art lens’s weight gain is due to its more sophisticated optical path, based on no less than 13 elements and including one complex aspherical element, plus three SLD (Special Low Dispersion) elements.
The build quality and the construction are first-rate throughout. Even so, whereas most of Sigma’s latest Art and Sports lenses feature weather-seals, they are lacking in this lens, which was one of the first out of the traps back in 2014. Based on a conventional ring-type ultrasonic system, autofocus is quick and whisper-quiet and comes complete with a focus distance scale beneath a viewing window. The flipside, compared with stepping motor-based systems, is that it’s still audible and lurches from one focus distance setting to another during movie capture.
Centre-sharpness is highly impressive when shooting wide-open at f/1.4, although mid- to corner-sharpness drops off noticeably more than with the Canon and Nikon lenses on test. That’s a moot point, however, as the Sigma has a faster maximum aperture. Either way, cornersharpness is strong at f/2.8, colour fringing is negligible, there’s virtually no distortion and the quality of the bokeh is pleasing. All in all, it's something of a modern classic.