Sigma 24-70mm F2.8 DG DN Art Review
The Sigma 24-70mm f2.8 DG DN Art for for Sony E-Mount and L-Mount is a new fast standard zoom lens for full-frame Sony, Leica, Panasonic and Sigma cameras.
It will also work with APS-C sensor cameras with an effective increase in focal length to 36-105mm due to the crop factor.
The Sigma 24-70mm f2.8 DG DN Art features a rounded 11 blade diaphragm which creates an attractive blur to the out of focus areas of the image.
It also offers a dust- and splash- proof construction, a stepping AF motor for fast and quiet autofocusing, a zoom lock switch, a configurable AFL button, and a minimum focusing distance of 18cm (at 24mm) and maximum reproduction ratio of 1:4.5 (at 70mm).
The Sigma 24-70mm f2.8 DG DN Art lens is priced at £1,049.99 / $1,099.99 in the UK and the USA, respectively.
Ease of Use
Weighing in at 830 grams and measuring nearly 12.5cm in length, the Sigma 24-70mm f2.8 DG DN Art is certainly a big and heavy lens given its focal length, although it's actually slightly lighter and shorter than its main rival, the Sony FE 24-70mm F2.8 GM (886g and 13.6cms).
As seen in the photos below, it complements a full-frame camera like the Sony Alpha A7 III that we tested it wit, although it feels somewhat out of place on a smaller APS-C body.
Build quality is excellent given the comparatively affordable price tag. 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 supposed to be more durable. The optical elements are made of high-grade glass.
In terms of features, the Sigma 24-70mm f2.8 DG DN Art offers almost everything that you need from a standard zoom lens.
This notably doesn't include built-in Vibration Reduction, though, with the lens relying on the camera body to supply this feature.
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.
The Sigma 24-70mm f2.8 DG DN Art lens has a generously sized focus ring, which is ridged for easier grip. There are no hard stops at the ends of the range, making it harder to set focus at infinity. Polariser users should be pleased that the 82mm filter thread doesn't rotate on focus.
The Lock function switch is a useful feature that helps protect the lens. Set the focal length to 24mm and move it to the Lock position to prevent the zoom mechanism from creeping when the camera is pointed down or in storage.
There is a dedicated Auto Focus Lock (AFL) button that can also be re-configured to assign various functions to the lens barrel.
When it comes to auto-focusing, the Sigma 24-70mm f2.8 DG DN Art is a very quick performer, taking about 0.10 seconds to lock onto the subject when mounted on the Sony Alpha A7 III that we tested it with.
We didn't experience very much "hunting" at all, either in good or bad light, with the lens accurately focusing almost all of the time. It's also a very quiet performer, which makes this lens equally well-suited to both video recording and more candid stills shooting.
The Sigma 24-70mm f2.8 DG DN Art ships with a good quality soft case and also a plastic petal-shaped lens hood with a locking mechanism (LH878-03).
At the 24mm focal length the angle of view is 84.1 degrees.
At the 70mm focal length the angle of view is 34.3 degrees.
Chromatic aberrations, typically seen as purple or blue fringes along contrasty edges, are not a problem for the Sigma 24-70mm f2.8 DG DN Art, even at the edges of the frame.
Distortion and Vignetting
With the lens set to its maximum aperture of f/2.8, there is some light fall-off in the corners at both ends of the zoom range. Stopping-down to f/5.6 virtually eliminates this.
There's also noticeable barrel distortion at the 24mm focal length and slight pincushioning at 70mm which is apparent in both the Raw files and uncorrected JPEGs.
Flare is a typical problem with wider-angle lenses, so we were curious to find out how the Sigma 24-70mm f2.8 DG DN Art fared in this respect.
As these examples shows the lens is is a little susceptible to flare when shooting directly into the sun, even with the supplied lens hood fitted, but overall it is well controlled thanks to the lens' Super Multi-Layer Coating.
The Sigma 24-70mm f2.8 DG DN Art produces quite nice sunstars when stopped-down to f/16 and f/22, as shown above and below.
The Sigma 24-70mm f2.8 DG DN Art isn't claimed to be a macro lens, but it delivers quite good performance nonetheless if you zoom to 70mm. It has a minimum focusing distance of 18cm / 38cm at 24mm/70mm, and a maximum magnification ratio of 1:4.5 when set to the 70mm focal length. The following example demonstrates how close you can get to your subject.
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 Sigma 24-70mm f2.8 DG DN Art lens, Sigma employed an iris diaphragm with 11 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.
In order to show you how sharp this lens is, we are providing 100% crops on the following pages.