Canon RF 70-200mm f/2.8L IS USM Lens Offering versatility and long reach in a notably sleek form factor, the Canon RF 70-200mm f/2.8L IS USM is a flexible telephoto zoom characterized by its bright design and advanced optics. The constant f/2.8 maximum aperture suits working in difficult lighting conditions and also enables greater control over depth of field. A sophisticated optical design comprises a series of specialized elements, which help to suppress a variety of aberrations throughout the zoom range for well-controlled imagery. An Air Sphere Coating has also been applied to suppress flare and ghosting when working in strong lighting conditions.