Covering a versatile wide-angle focal length range, the RF 15-35mm f/2.8L IS USM from Canon is also characterized by its bright f/2.8 constant maximum aperture. This bright design enables working in available light conditions and also affords greater control over depth of field. The range of wide focal lengths suits working in a variety of situations, from landscape to documentary shooting, and this zoom is complemented by an advanced optical design that greatly reduces color fringing and distortion for high clarity and sharpness. An Air-Sphere coating has also been applied to reduce flare and ghosting for improved contrast and color fidelity when working in bright conditions.Complementing the imaging capabilities is an apt Nano USM focus system, which delivers fast, nearly silent autofocus performance with full-time manual focus override. An Image Stabilizer also compensates for up to five stops of camera shake to help produce sharper handheld shots in difficult 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 15-35mm is weather-sealed and has a fluorine coating to protect the front and rear elements.