Sigma isn’t short of fast primes in its lineup, so where does this latest addition fit in? Michael Topham takes a closer look
Sigma 40mm f/1.4 DG HSM Art review: Features
The first thing that’s obvious when you inspect this lens is its large size and how much heavier it feels in the hand than the 35mm f/1.4 DG HSM Art and 50mm f/1.4 DG HSM Art. I’ll touch on this in more detail shortly, but in order to achieve the company’s goal of creating the finest optical quality for full-frame DSLR and mirrorless cameras offering a 50-million-pixel resolution, Sigma’s engineers first had to work out the best optical formula.
It’s the first 40mm f/1.4 lens the company has ever made and the construction unites 16 elements in 12 groups – a more complex arrangement than the 13 elements in 11 groups found inside the 35mm f/1.4 DG HSM Art and the 13 elements in 8 groups you get inside the 50mm f/1.4 DG HSM Art.
To keep chromatic aberration in check, the lens arranges three FLD (‘F’ Low Dispersion) glass elements and three SLD (Special Low Dispersion) glass elements together. The front element features a water and oil repellent coating that allows it to be easily cleaned in challenging shooting environments and Sigma’s Super Multi-Layer Coatings are once again employed to curtail flare and ghosting when shooting directly towards the light.
Sigma is clearly very proud of the way the lens handles distortion, claiming a distortion figure of less than 1%. Just as we’ve seen many times before, the lens is equipped with Sigma’s Hyper Sonic Motor (HSM), licensing fast and quiet focusing and full-time manual focusing, whereby users can adjust the focus manually at any time without the need to flick the AF/MF switch to manual first.
The lens’s nine-bladed aperture diaphragm offers settings from f/1.4 to f/16. Used at its maximum aperture, these nine aperture blades are designed to create an attractive blur in the out-of-focus areas of an image, with pleasing spherical bokeh in the highlights. The minimum focus distance is 40cm and what with it being considerably larger than the 35mm f/1.4 DG HSM Art and 50mm f/1.4 DG HSM Art, it won’t come as a great surprise that filters and adapters are mounted via an 82mm thread rather than a 67mm or 77mm one.
As well as being made in the usual Canon, Nikon and Sigma mounts, it’s also one of Sigma’s new lenses to be offered in E-mount for Sony users, ruling out the need for a Sigma MC-11 converter. The Sony E-mount version performs the same functions as the converter, including in-camera image stabilization and in-camera lens aberration correction, with the benefit of it also being compatible with Sony’s continuous AF modes, which are not supported by the MC-11.