The constant f/4 maximum aperture strikes a balance between being bright enough for available light shooting while also contributing to the especially portable, handholdable design. Complementing this is an apt Optical Image Stabilizer, which compensates for up to 5 stops of camera shake, or up to an impressive 7.5 stops of shake correction when paired with an EOS R-type body with IBIS.
Optically, this lens incorporates four UD elements, which suppress a variety of aberrations throughout the zoom range for high clarity, and an Air Sphere Coating is also featured to reduce flare and ghosting. Balancing the distinguished optical system is a Dual Nano USM focus system, which delivers fast, nearly silent autofocus performance with full-time manual focus override. Additionally, this 70-200mm is weather-sealed and has a fluorine coating to protect the front and rear elements.
