The Canon EF 16-35mm f/4L IS USM is an ultra wide-angle zoom lens designed for full-frame cameras, making it a versatile choice for capturing expansive landscapes or tight architectural spaces. It features a constant maximum aperture of f/4 and an optical image stabilizer that provides up to four stops of shake correction, which helps you keep handheld shots sharp even in lower light. The focus is handled by a ring-type ultrasonic motor for quiet and fast operation, while the inner focusing system ensures the lens length doesn't change during use. Built for durability, the lens incorporates a fluorine coating on the front element to repel smudges and moisture, and it is designed to be dust and water-resistant when paired with a compatible protect filter. Its optical design uses 16 elements, including three aspherical and two ultra-low dispersion elements, to maintain clarity across the wide frame. Weighing 615g and measuring 112.8mm in length, it remains portable for travel photographers who need a wide perspective without excessive bulk. The package includes an EW-82 lens hood and an E-77 II cap, fitting a 77mm filter thread.