SIGMA 105MM F/1.4 DG HSM | A

Billed as the ‘bokeh master’, this Sigma Art lens is a heavyweight contender

Available in a wide range of mount options, including Canon

EF, Nikon F, Sony FE and Leica L, as well as Sigma’s proprietary mount, this lens matches the Nikon on test with its upsized 105mm focal length and fast f/1.4 aperture rating. However, it’s significantly larger and much heavier than the Nikon, weighing in at 1,645g. To put that into perspective, it’s about the same weight as most 70-200mm f/2.8 telephoto zooms. It comes complete with a tripod mount ring. It’s a high-quality ring at that, with a foot that’s directly compatible with the industry-standard ArcaSwiss mounting socket.

Not just large, the lens also has a complex optical path based on 17 elements. These include three top-performance

FLD (‘Fluorite’ low dispersion) elements, two SLD (special low dispersion) elements, and an aspherical element. Sigma’s usual Super Multi-layer coating is on hand to minimise ghosting and flare, and a fluorine coating is applied to the front element. Weather-seals are also featured.

As with the Nikon lens on test, the combination of focal length and wide aperture enables an ultra-tight depth of field that marginally undercuts that of Canon’s 85mm f/1.2 lenses. Again, the ring-type ultrasonic autofocus is fast and accurate, and comes complete with full-time manual override, as well as a focus-distance scale.

Both axial and lateral chromatic aberration are very negligible with the Sigma lens, and the overall quality of bokeh is beautifully smooth. There’s no lack of sharpness and contrast when shooting wide open either, but if anything the depth of field can be a little too tight in some shooting scenarios. Even so, bokeh remains very good when stopping down a bit, adding to the lens’s versatility.

A bruiser Unlike every other lens in this test group, the heavyweight Sigma comes complete with a tripod mounting ring Sharpness Levels of sharpness are remarkably similar to those of the Nikon lens, although the Sigma is slightly sharper in the interim region between the centre and corners at wide apertures Colour fringing Both lateral and axis chromatic aberration are slightly more negligible than in the Nikon lens, and better wide open than in the Canon EF lens Distortion There’s the smallest hint of pincushion distortion that will generally go unnoticed