Sigma 17-40mm art lens put to the test

Sigma’s latest addition to its Art lens lineup, the 17–40mm F1.8 DC Art, brings an ambitious combination of high-speed aperture, weather-sealed construction, and extended focal range tailored for APS-C mirrorless systems. As the successor to the much-loved Sigma 18–35mm F1.8 for DSLRs, this mirrorless-native zoom seeks to reclaim its position as the brightest zoom option for cropped sensors, now with a wider focal span and lighter footprint. The lens has been put to rigorous real-world testing, particularly in astrophotography settings where stars quickly expose any optical compromises.

Sigma 17-40mm art lens put to the test: A welcome revival for APS-C shooters

The release of the Sigma 17–40mm F1.8 DC Art signals a commitment to APS-C photographers, a group often overlooked in favor of full-frame systems. With mounts available for Sony E, Fujifilm X, Canon RF, and L-Mount cameras, Sigma is embracing a broad segment of the mirrorless market. This lens targets users who value versatility, low-light performance, and optical quality, making it especially relevant for those who shoot nightscapes, travel scenes, and creative video content.

Covering an effective full-frame equivalent range of approximately 26mm to 60mm, the lens spans from moderately wide to standard focal lengths. This makes it ideal for foreground-rich Milky Way scenes and daytime landscapes alike. The standout feature is, of course, its constant F1.8 aperture across the entire zoom range, a feat no other APS-C zoom on the market can currently match.

The 17–40mm F1.8 fits within Sigma’s Art series, known for high-end optics and meticulous design. The lens weighs 535g and measures well for mirrorless form factors, though it remains substantial given the wide aperture. Still, it is noticeably lighter than its 18–35mm predecessor by over 30%. Its internal zoom mechanism maintains a constant physical length throughout the zoom range, making it gimbal- and tripod-friendly. The inclusion of a weather-sealed structure and a water-repellent front coating further underscores its field-readiness.

Physically, the lens includes an aperture ring with click deactivation and locking mechanisms, dual customizable AFL buttons, and a 67mm front filter thread. Autofocus is driven by Sigma’s HLA motor, designed for fast, quiet, and precise performance in both photo and video contexts.

Where this lens truly distinguishes itself is under the night sky. When mounted on a Sony APS-C camera and pointed at the core of the Milky Way, it demonstrated impressive light-gathering capabilities at F1.8. Stars remained small and crisp in the image center, even at maximum aperture, but moderate coma was visible in the corners, especially on the right side of the frame. This is typical of fast lenses, particularly zooms, and was not unexpected given the wide-open test conditions.

Stopping down to F2.8 significantly improved edge performance. The upper left and right corners became much sharper, with stars resolving more cleanly and coma distortion largely mitigated. Interestingly, the asymmetrical nature of the coma suggested potential decentering in the copy used, though this effect normalized when framing shifted and corner stars reversed roles.

At both ends of the focal range, 17mm and 40mm, the lens delivered solid results. At 17mm, the view was wide enough for layered astrophotography compositions. At 40mm, mounted on a tracker for longer exposure capability, the lens still performed admirably at F1.8. Star distortion remained minimal and uniformly distributed across the frame. At F2.8, the performance turned exceptional, with pinpoint stars across the entire field and minimal chromatic aberration.

What’s remarkable about the 17–40mm F1.8 is that it behaves more like a set of fast primes than a traditional zoom. Throughout the test sessions, its output at F2.8 rivaled the results from prime lenses costing nearly as much, but with none of the focal length constraints. This makes it a highly compelling travel companion for astrophotographers who want to switch seamlessly between wide vistas and more intimate compositions without changing lenses.

The field test confirmed that the lens is not without flaws. Coma and sharpness drop-offs exist at F1.8, particularly in the corners. But considering this is an ultra-fast zoom covering a broad focal range, its weaknesses are mild and predictable. And more importantly, the lens remains entirely usable wide open, delivering excellent center sharpness and enough edge clarity to justify its top-tier billing.

The Sigma 17-40mm F1.8 DC Art is an innovative piece of glass for APS-C mirrorless shooters. In daylight, it produces creamy bokeh and high contrast. At night, it offers the brightness and flexibility needed to capture detailed Milky Way panoramas without being tethered to prime lens limitations. Its build quality and weather sealing allow it to perform in demanding environments, while the optical performance lives up to the expectations set by Sigma’s Art designation.

Astrophotographers looking for a fast zoom with superior optical integrity, especially one that complements a compact mirrorless system, will find a strong contender here. It might not fully replace all specialty primes, but it can easily reduce the number of lenses needed in the field, an especially attractive proposition for travel and landscape shooters.

Sigma 17-40mm art lens put to the test specifications

• Focal Length: 17–40mm (approx. 26–60mm full-frame equivalent)
• Maximum Aperture: Constant F1.8
• Mount Options: Sony E, Fujifilm X, Canon RF (APS-C only), L-Mount
• Minimum Aperture: F16
• Lens Construction: High-precision aspherical elements with advanced optical coatings
• Aperture Blades: 11-rounded diaphragm for smooth bokeh
• Autofocus Motor: HLA (High-response Linear Actuator)
• Zoom Type: Internal zoom
• Minimum Focus Distance: ~11.8 in / 30 cm
• Filter Thread Size: 67mm
• Weight: 535g (approx. 1.18 lbs)
• Length: Varies by mount, approx. 5 inches
• Weather Sealing: Yes, dust- and splash-resistant body with water/oil-repellent front coating
• Included Accessories: Petal-type lens hood (LH728-02), front cap, rear cap
• MSRP: €999 (approx. $1,099 USD)

 

The BRIGHTEST Zoom for APS-C! Tested for Astrophotography

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