Sigma 17-40mm f/1.8 DC Art Lens Canon RF

Key Features

• APS-C format | f/1.8 to f/16 aperture range
• Equivalent to 25.5 to 60mm on full-frame
• Superfast wide-to-normal zoom
• High Linear Actuator (HLA) autofocus
• Minimum focus distance of 28 cm
• Control ring for manual adjustments
• Special Low Dispersion (SLD) and aspherical lens elements
• Water- and oil-repellent coating on front element
• Dust- and splash-resistant construction

Optical Design and Performance

The Sigma 17-40mm f/1.8 DC Art lens features 16 elements arranged in 12 groups, including four aspherical and four Special Low Dispersion elements to minimize flare, ghosting, and various aberrations. This optical design delivers prime-like sharpness and image quality comparable or superior to other Sigma Art lenses such as the 18-35mm f/1.8 DC HSM Art. The 11-blade rounded diaphragm produces smooth, pleasing bokeh when shooting wide open.

The lens maintains a bright constant f/1.8 aperture throughout the zoom range, enabling excellent low-light performance and creative depth of field control. It also offers a close minimum focusing distance of 28 cm (11 inches) and a maximum magnification ratio of 1:4.8 at 40mm, enhancing versatility for close-up and tight space shooting.

Video and Handling Features

Designed with video creators in mind, the lens has an internal zoom mechanism that keeps its length constant during zooming, facilitating balance on gimbals and stabilizers. It suppresses focus breathing for smooth focal transitions. The high-speed, quiet linear autofocus motor ensures accurate focusing, while a knurled control ring allows precise manual focus and exposure adjustments.

• Two AFL (autofocus lock) buttons for customizable control
• Focus mode switch for quick toggling between autofocus and manual focus
• Durable brass bayonet mount for secure camera attachment

Physical Specifications

• Filter thread size: 77 mm
• Dimensions: 88.2 mm diameter x 122 mm length
• Weight: 940 g

Included in the Package

• Sigma 17-40mm f/1.8 DC Art Lens for Canon RF mount
• Sigma LCF-67 IV Lens Cap (67 mm)
• Sigma LCR III Rear Lens Cap for Canon RF
• Lens hood
• Carrying pouch