The best thing about Sigma Art lenses, from a buyer’s and tester’s point of view, is that all are similarly well built and optically outstandingly good. Buyers are undoubtedly pleased that all Art lenses play in the same league and that you can assume a similar high quality for every further lens if you already own one of the “A” series. You could almost buy a further one blindfolded. For blogging/testing, being able to refer to previous tests is a clear advantage, as it saves you a lot of typing. 😉 So far, the 30mm f1.4 Art, 35mm f/1.4 Art and, just recently also the 18-35mm f1.8 Art, have found their way into my photo bag. I already tested the 30mm A (Link) and the 35mm A (Link) and compared them here. Let’s now move on to the 18-35mm f/1.8 Art. 😉
Build quality and handling
As already mentioned, the 30mm A, 35mm and 18-35mm have a very similar design and feel, and are comparably well built. All three have a metal mount and a smoothly and evenly turning focus ring that won’t be accidentally adjusted thanks to moderate resistance. As it is a zoom lens, the 18-35mm comes with an appropriate zoom ring offering a little more resistance, but it can still be comfortably turned and doesn’t feel too stiff. The AF/MF buttons of all three look similar, if not identical, and snap fully into place. All three lenses make a solid and robust appearance, although the 35mm and the 18-35mm leave an even better impression due to their size and weight. Both lenses are comparably broad, but the 18-35mm is almost three cm longer. The 30mm A is the smallest among the three lenses.
There are many image quality tests of the 18-35mm under laboratory conditions on the web. As for myself, I haven’t yet shot any dull brick wall photos with this lens – but I will, when I find time to compare the 18-35mm with the 35mm. This is why I cannot tell for sure how good its resolution is. I’d assume it is almost as good as the outstanding 35/1.4 Art. I consider it fully suitable for shooting with wide open aperture. I haven’t been able to find disturbing amounts of CAs, distortion and vignetting yet. From an optical point of view, the 18-35mm f1.8 Art is undoubtedly the best zoom lens I ever had the pleasure of using.
The three Arts are not only similar in terms of design and build quality; but also in terms of autofocus, the three lenses are hardly distinguishable. The only perceivable difference is the noise. The 18-35mm A focuses so silently, you might think the AF is turned off. Without a doubt, this is the most silently focusing lens I ever had on one of my cameras. Despite the unparalleled low level of noise, the AF works just as quickly as on the other two Arts. It is sufficiently quick for all subjects you might want to photograph with a standard zoom.
The 18-35mm f/1.8 Art is a unique lens in many ways. It is the fastest zoom for DSLRs, but also one of the zooms with the smallest zoom range. The advantage in light gathering power is de facto as important as the disadvantage of small zoom range and the non-existent image stabilizer. Even though it might sound absurd, I rather consider it a substitute for several fixed focal lengths (18/1.8, 24/1.8, 35/1.8) than for any common 17-5X f2.8 standard zoom. And here it is fully convincing. Firstly, I have no knowledge of any APSC system that offers a 18/1.8 fixed focal length. Secondly, it is undoubtedly smaller, lighter, and cheaper than these three fixed focal length, if all of them existed, would be. Thirdly, more than any other zoom, it is fully suitable for wide open aperture work and gets very close to fixed focal lengths in terms of image quality. Some comparisons in photography forums even see it ahead of many fixed focal lengths. I’d say you should definitely have a closer look at this lens if you’re not discouraged by the weight and size of the 18-35/1.8 Art. The following sample images are available on Flickr in full resolution (15 megapixels), just click on the photos to view them in full size.