Sigma 20mm f/1.4 DG HSM | A ("Art") - Full Format Review / Lens Test
Lens Reviews - Canon EOS (Full Format)
Article Index
Introduction
Analysis

Review by Klaus Schroiff, published March 2016

Introduction

During the last decade the ultra-wide segment has been dominated by zoom lenses but it seems as if prime lenses are about to enter a renaissance. Lately Nikon released a 20mm f/1.8 and we've seen a bunch of updates from Zeiss and some promising announcements from a new player (irixlens.com). Now Sigma wouldn't be Sigma if they didn't come up with their own interpretation of the topic - the new Sigma 20mm f/1.4 DG HSM | Art. The most significant feature is, of course, the speed - at f/1.4 it is the fastest lens of its kind (on full format cameras at least). The price tag is surprisingly moderate at "just" 900US$/1000EUR. Despite being wider it is also cheaper than Canon's EF 24mm f/1.4 USM L II for instance.

Sigma's "Art" series tend to have a superb build quality and the 20mm f/1.4 is no exception to this rule. Besides some metal parts, Sigma uses a new material called TSC (Thermally Stable Composite) which contributes to the high quality perception. The broad focus ring is nicely rubberized and operated smoothly. The physical length of the lens remains constant thanks to internal focusing. A petal-shaped (plastic) lens hood is built in - thus non-detachable. However, there are also a few downsides - the lens isn't weather-sealed nor does it accept front filters due to the bulb-like shape of the front element (see below). The high speed also comes at a price - it's a fairly massive and heavy-weight lens. Just to give you a rough framework for comparison - albeit not really a valid one - the slower Canon EF 20mm f/2.8 USM has a size/weight of less than half of the Sigma.

The lens features HSM, which is Sigma's version of an ultrasonic drive. Typical for many HSM lenses, the AF is virtually silent and very fast - at least in conventional phase-detection AF mode. Contrast AF in Live-View mode is usable and has improved quite a bit in the latest DSLR generation. The lens is also compatible with Sigma USB dock so you can tune the AF calibration at will if you see the need and are willing to invest a little extra.

Here's a closer look at the front element of the lens.

Specifications
Optical construction15 elements in 11 groups including 4xSLD, 2xFLD and 2x aspherical elements
Number of aperture blades9 (rounded)
min. focus distance0.276m (max. magnification ratio 1:7.1)
Dimensions90.7x129.8mm
Weight950g
Filter size-
Hoodpetal-shaped (bayonet mount, supplied)
Other features-