The Canon EF 16-35mm f/4 L IS USM is a premium ultra-wide-angle zoom lens designed for Canon EF-mount DSLRs, delivering professional-grade optical performance in a compact package. Featuring a constant f/4 maximum aperture, this L-series lens incorporates a sophisticated optical design with three aspherical elements and two ultra-low dispersion (UD) elements to minimise distortion and chromatic aberration across the entire zoom range. The integrated 4-stop optical image stabilisation system enables sharp handheld shots even in low light, whilst the ring-type ultrasonic motor (USM) provides fast, accurate, and silent autofocus with full-time manual override. Built to withstand challenging conditions, the lens features dust and water resistance (when paired with an optional Canon PROTECT filter) and a fluorine coating on exposed elements. With a minimum focus distance of 28cm, the EF 16-35mm f/4 offers exceptional versatility for landscape, architectural, and travel photography. Weighing just 615g with a 77mm filter diameter, it strikes an excellent balance of capability and portability.