As the first website worldwide, SLRGear.com had the opportunity to thoroughly test the Sigma 24-35mm f/2 DG HSM Art. According to a Review on Imaging-Resource’s partner website, the 24-35/2 A has very similar imaging qualities to its crop sibling (18-35/1.8 A).
The newest Art is said to be very sharp in the middle of frame at maximum aperture, both when used on FF and Crop cameras. The image corners, which are trailing a little behind on FF, already catch up again at f/2.8 and are excellent at f/4. There are some CAs, but these are said to be rather weak over the entire focal length and aperture range. The case is apparently more or less the same in regards to distortion – the highest value determined for the 24mm was 0.8%, which is negligible in real world use. The only fly in the ointment is vignetting, which came in at the relatively high value of 1.25 EV at 24 mm and f/2. However, after stopping down to f/2.8 vignetting was reduced to a moderate value of 0.75 EVs. Taking all these results into consideration, it is not surprising that the conclusion is exceedingly positive:
We think Sigma has done it again! Sigma once again dares to be different and builds a unique lens not offered by the major manufacturers. In what is essentially a range of fast prime lenses built into a single zoom lens, the new Sigma 24-35mm is stunning with super-sharp images, even when shot wide open. Combined with its fantastic build quality and excellent AF performance, the Sigma 24-35mm ƒ/2.0 Art lens is a great option for street shooters, concert and event photographers, even landscape and astrophotographers; or just about any full-frame DSLR owner looking for stunning sharpness and excellent low-light performance.
However, since pictures do not necessarily have to concur with measurements, Sigma US published a series of photos on their blog. There you can see a, for a wide angle zoom, rather appealing Bokeh.