Introduction

Ease of Use

Weighing in at 1645 grams and measuring 13.2cm in length, the Sigma 105mm F1.4 DG HSM is a very big lens considering its modest focal length, and is significantly larger and heavier than most other lenses of its type.

As seen in the photos below, it complements a full-frame camera like the Canon EOS 5DS R quite well, although the presence of a tripod collar/foot indicates that this lens is best suited to life mounted on a tripod. Having said that, the collar can actually be completely removed for easier, and lighter, handholding.

Build quality is excellent. The lens has a plastic shell with a mixture of metallic parts and a compound material, TSC (Thermally Stable Composite), used inside. It also incorporates a brass bayonet mount that's claimed to be more durable. The optical elements are made of high-grade glass. The focus ring is very wide, nicely damped and ridged for easier grip.

In terms of features, the Sigma 105mm F1.4 DG HSM offers all the basics that you need from a prime lens. The main exception is the lack of built-in Vibration Reduction, although the very fast maximum aperture of f/1.4 helps to make up for this.

Focusing is usefully internal and manual focusing is possible when set via the Focus switch on the lens barrel. Full-time manual focus override is also available at any time simply by rotating the focus ring. A clear distance scale in both feet and meters runs from the closest focusing distance of 100cm / 39.4in to infinity.

The Sigma 105mm F1.4 DG HSM lens has an enormously wide focus ring. There are hard stops at both ends of the range, making it easier to set focus at infinity. Polariser users should be pleased that the massive 105mm filter thread doesn't rotate on focus.

When it comes to auto-focusing, the Sigma 105mm F1.4 DG HSM zoom isn't the quickest performer, taking about 0.35 seconds to lock onto the subject when mounted on the Canon EOS 5DS R that we tested it with.

We didn't experience too much "hunting", though, either in good or bad light, with the lens accurately focusing almost all of the time. It's also a quiet performer, thanks to the built-in HSM (Hyper Sonic Motor), which makes this lens well-suited to video recording.

The Sigma 105mm F1.4 DG HSM ships with a good quality soft case and strap, a protective cover that can be fitted when the tripod collar is removed, and also a large carbon fiber reinforced plastic round lens hood.

Focal Range

The 105mm focal length provides an angle of view of 23.3 degrees.

 

Chromatic Aberrations

Chromatic aberrations, typically seen as purple or blue fringes along contrasty edges, are only conspicuous by their almost complete absence from our test shots. The examples below show the worst-case scenario.

Light Fall-off

With the Sigma 105mm F1.4 DG HSM set to its maximum aperture of f/1.4, there is significant light fall-off in the corners. Stopping-down to f/4 virtually eliminates this.

Macro

The Sigma 105mm F1.4 DG HSM isn't claimed to be a macro lens, with a minimum focusing distance of 100 cm / 39.4in and a maximum magnification ratio of 1:8.3. The following example demonstrates how close you can get to your subject.

Close-up performance

Bokeh

Bokeh is a word used for the out-of-focus areas of a photograph, and is usually described in qualitative terms, such as smooth / creamy / harsh etc. In the 105mm F1.4 DG HSM lens, Sigma employed an iris diaphragm with 9 rounded blades, which has resulted in very nice bokeh in our view. We do realise, however, that bokeh evaluation is subjective, so we've included several 100% crops for your perusal.

f/1.4

f/1.8

f/2

f/2.8

f/4

f/5.6

f/8

f/11

f/16

Sharpness

In order to show you how sharp this lens is, we are providing 100% crops on the following page.