Constant f/4 maximum aperture affords consistent performance throughout the zoom range and also contributes to the relatively lightweight design and compact form factor. An Air Sphere Coating (ASC) has been applied to lens elements to reduce backlit flaring and ghosting for maintained light transmission and high contrast in strong lighting conditions. Dual Nano USM system utilizes both a ring type USM and an STM mechanism to realize quick and accurate focusing that is also smooth and nearly silent to suit both photography and video applications. This focusing system also affords full-time manual focus control when working in the one-shot AF mode. A protective fluorine coating has been applied to the front and rear elements to resist fingerprints and smudges and to make cleaning these elements significantly easier. Ideal for travel, sports, and wildlife thanks to its compact size and lightweight, the RF 70-200mm F4L IS USM has pro features in small size and won’t take up much room in a kit bag. Designed for stable handheld shooting, the Optical Image Stabilizer gives great confidence, with up to 5-stops available. the RF 70-200mm F4L IS USM gives you the freedom to compose your perfect shot.