The Sigma 24mm f/1.4 DG HSM Art follows suit with the company’s previous 35mm and 50mm Art-line lenses, maintaining the same f/1.4 aperture rating, while extending the wide-angle viewing potential. Compared with the 63.4-degree viewing angle of the 35mm lens, this one stretches the envelope to a much more generous 84.1 degrees (measured on the diagonal, using a full-frame body).
Mount: Canon EF, Nikon F, Leica L, Sigma, Sony E
Lens construction: 15 elements in 11 groups
Angle of view: 84.1 degrees
Diaphragm blades: 9
Minimum aperture: f/16
Minimum focusing distance: 0.25m
Maximum magnification ratio: 0.19x
Filter size: 77mm
Starting at the back and moving forwards, the 24mm lens follows the same design ethic as the 35mm and 50mm Art lenses. As such, it features a high-quality brass mounting plate that enables compatibility with Sigma’s optional USB dock for firmware updates and customization, along with metal and TSC (Thermally Stable Composite) barrel parts. There’s a focus distance scale under a viewing window with depth of field markings for f/8 and f/16 apertures towards the rear, and a comfortably wide and super-smooth focus ring towards the front.
Focusing is completely internal so the front element neither extends nor rotates. Autofocus is extremely rapid, precise and whisper-quiet, based on a ring-type ultrasonic system that features the usual full-time manual override. Typical of up-market Sigma lenses, a petal shaped lens hood and soft case are included.
Under the skin, the internals are similarly impressive, featuring three FLD (F Low Dispersion) elements of equal optical performance to top-grade fluorite glass, four SLD (Special Low Dispersion) elements and two aspherical elements. ‘Super Multi-Layer Coatings’ are applied to reduce ghosting and flare, and a nine-blade diaphragm enables well-rounded apertures.
Overall, the build quality and handling of the lens are absolutely superb, although it’s not a weather-sealed design. The Sigma 50mm Art lens is something of a Goliath but this 24mm optic has a more manageable size and weight.
Wide-angle lenses often lack sharpness towards the edges of the frame but the Sigma does well to retain corner-to-corner sharpness even at its widest f/1.4 aperture, where vignetting is also fairly well controlled. Stop down to f/2.8 and corner-sharpness as well as peripheral illumination both become excellent. Resistance to ghosting and flare is similarly impressive, while chromatic aberrations and distortion are both minimal. Suffice it to say that the high-quality build is matched by optical excellence of the highest order.
We run a range of lab tests under controlled conditions, using the Imatest Master testing suite. Photos of test charts are taken across the range of apertures and zooms (where available), then analyzed for sharpness, distortion and chromatic aberrations.
We use Imatest SFR (spatial frequency response) charts and analysis software to plot lens resolution at the center of the image frame, corners and mid-point distances, across the range of aperture settings and, with zoom lenses, at four different focal lengths. The tests also measure distortion and color fringing (chromatic aberration).
Corner-to-corner sharpness is very impressive even wide-open at f/1.4 and become absolutely fabulous at f/2.8 and narrower apertures.
Both axial and lateral chromatic aberrations are negligible, even when uncorrected in-camera or at the editing stage.
There’s a touch of barrel distortion but it’s only slight and very easily corrected, if you feel the need.
Continuing the trend set by previous Sigma Art-line lenses, this 24mm prime is beautifully built and delivers exceptional image quality. It’s a fully professional-grade lens that’s available at a much more affordable price than the equivalent own-brand lenses from camera manufacturers. If you like shooting at 24mm and want something faster than your standard zoom, look no further.