Capture striking architecture and expansive landscapes with this ultra-wide-angle L-series lens. Shoot hand-held and in low light conditions with a fixed aperture of f/4. Get closer to your subjects with 0.28 m focusing distance through the entire zoom range. Ensure accurate colour balance and enhance contrast along with reduced ghosting and flare with Super Spectra coating. Produce sharp, high-contrast images with Super UD (ultra-low dispersion) elements to suppress chromatic aberrations. Be prepared for split-second moments with a fast, responsive Auto Focus with Ultra-Sonic Motor (USM). Use specialised filters, such as polarisers and graduates with ease thanks to the non-rotating lens. Compatible with all DSLR cameras including full frame and EOS M mirrorless with an EF-EOS M Mount adapter. The EF 17-40mm f/4L USM Lens is an ultra-wide-angle lens producing stunning clarity in a range of focal lengths. Its compact, lightweight body makes it an ideal travel companion - suited to interiors, architecture and landscapes, fitting more in the frame without the need to step back. Produce consistent exposures with the large f/4 aperture over the 17-40 mm zoom range and create softer background blur with a 7-blade circular aperture diaphragm. Part of the Canon professional L-series flagship range, its designed for robust handling and resistant to dust and moisture. Lens system Minimum aperture number 4 Closest focusing distance 0.28 m Maximum aperture number 22 Number of diaphragm blades 7 Lens mount interface Canon EF Focal length range 17 - 40 mm Lens viewing angle, diagonal 104 - 57.5° Lens type Wide zoom lens Lens structure (elements/groups) 12/9 Component for SLR Performance Auto focus Yes Manual focus Yes AF actuator USM Design Product colour Black Weight & dimensions Weight 500 g Length 96.8 mm Filter size 77 mm Diameter 8.35 cm Other features Magnification 0.24x