Sigma Art 17-40mm f/1.8 DC Review

Alright, let's talk about this Sigma 17-40mm f/1.8. It's a weird one, but in a good way. It's a zoom lens that acts like a prime, giving you a super bright f/1.8 aperture across the entire range from 17mm to 40mm. That's a full-frame equivalent of about 25.5mm to 60mm on your Sony APS-C camera, so you're covered from wide-angle to a short telephoto.

The image quality is the star here. It scores in the 92nd percentile for optics, so yeah, it's sharp. The bokeh is also top-tier at the 89th percentile, which makes sense for an f/1.8 lens. But the autofocus is just okay, landing in the 47th percentile. And there's no stabilization, so you'll need steady hands or good light for slower shutter speeds.

At $919, this lens isn't cheap. You're paying a premium for that constant f/1.8 aperture and Sigma's Art-series optical quality. If you absolutely need that bright aperture across a zoom range, it's your only option. But if you can live with variable aperture zooms or a collection of primes, you can save a lot of cash.

Compared to primes like the Viltrox 35mm f/1.7 or the Meike 55mm f/1.8, this Sigma gives you flexibility without sacrificing aperture. Those primes will be smaller, lighter, and often cheaper, but you lose the zoom. Against a standard zoom like a kit lens (f/3.5-5.6), this Sigma blows it away in low-light performance and background blur, but you pay for it in size, weight, and cost.

Buy this if you're a Sony APS-C shooter who does portraits or low-light work and you really want the convenience of a zoom with a prime lens's aperture. It's a specialist tool. If you're a traveler worried about weight, or you need lightning-fast autofocus for sports, look elsewhere.