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 An Air Sphere Coating has also been applied to suppress flare and ghosting when working in strong lighting conditions. A unique Control Ring is also integrated into the lens design for intuitive control over exposure settings from the lens itself. Additionally, this 70-200mm is weather-sealed and has a fluorine coating to protect the front and rear elements. Bright f/2.8 constant maximum aperture maintains consistent illumination throughout the zoom range and suits working in low-light conditions as well as affords increased control over depth of field for working with selective focus techniques. This focusing system also affords full-time manual focus control when working in the one-shot AF mode.