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

The Sigma 17-40mm f/1.8 DC Art is a third-party wide-to-normal zoom lens designed for APS-C mirrorless cameras, covering a 27.2-64mm full-frame equivalent focal range on Canon RF mount with a constant f/1.8 maximum aperture maintained across the entire zoom range. Optical construction consists of 17 elements in 11 groups, incorporating four aspherical and four Special Low Dispersion elements to control aberrations, flare, and ghosting. An inner zoom mechanism keeps the overall length constant throughout the focal and focus range, adding stability during handheld, tripod, and gimbal use. Autofocus is handled by Sigma’s HLA (High-response Linear Actuator) system, delivering fast and quiet operation suitable for both stills and video. An 11-blade rounded diaphragm supports smooth bokeh rendering when shooting wide open, and the minimum focus distance of 11 inches is maintained across the full zoom range. The Canon RF version features a control ring for assignable camera functions.

– Canon RF mount, APS-C format
– 17-40mm focal length (approx. 27.2-64mm full-frame equivalent on RF)
– Constant f/1.8 maximum aperture
– 17 elements in 11 groups; 4 aspherical and 4 SLD elements
– HLA (High-response Linear Actuator) autofocus
– Inner zoom mechanism; constant length during zoom and focus
– 11-blade rounded diaphragm
– 11″ minimum focus distance across entire zoom range
– Control ring for assignable functions (RF version)
– Dust and splash resistant construction
– 67mm filter thread