Sigma A 17-40 mm f/1.8 DC review - Introduction

Have you rated your lenses yet?

Sigma A 17-40 mm f/1.8 DC

25 August 2025

Maciej Latałło

1. Introduction

In April 2013 the Japanese Sigma company surprised everyone by presenting a very original lens, the A 18-35 mm f/1.8 DC HSM designed for reflex cameras with an APS-C/DX sensor. The focal range in this case was narrower than the focal range of typical kit lenses but the fast, constant aperture of f/1.8 impressed us a lot.

Over two years later, in June 2015, Sigma made a very similar move in the segment of full frame reflex cameras by releasing the A 24-35 mm f/2.0 DG HSM. A bit later, in February 2016, the A 50-100 mm f/1.8 DC HSM designed for smaller sensors was added to the line-up of fast zoom lenses, an excellent complementation of the 18-35 mm f/1.8 lens released almost three years earlier. The following chart presents a comparison of parameters of these truly unique lenses.

Sigma A 17-40 mm f/1.8 DC - Introduction

As this strategy worked perfectly well in case of reflex cameras you could expect a similar move in the mirrorless sector. After all a clever company not only copies their successful strategies but also tries to move forward a bit with every new launch. In such light the release of the Sigma A 28-45 mm f/1.8 DG DN that took place in June 2024 was a perfectly understandable move. Although the range is a tad different than in case of reflex cameras, making some potential customers complain about the lack of a wider angle, the presence of a better aperture fastness, that of f/1.8, makes up for it.

Please Support Us

If you enjoy our reviews and articles, and you want us to continue our work please, support our website by donating through PayPal. The funds are going to be used for paying our editorial team, renting servers, and equipping our testing studio; only that way we will be able to continue providing you interesting content for free.

- - - - - - - - - - - - - - - - - advertisement - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

When it comes to the mirrorless successor of the Sigma A 18-35 mm f/1.8 DC HSM there is no doubts and no reasons to complain. In June 2025 the 17-40 mm f/1.8 DC was shown with a sensational f/1.8 aperture and a focal range that was increased from both sides.

Such unique constructions always interest us the most – small wonder the production version of the Sigma A 17-40 mm f/1.8 DC soon found a way to our editorial office to be thoroughly tested. It was sent courtesy of K-Consult, the Polish distributor of Sigma products for Poland – thank you very much!