Combining the versatility of a zoom with the speed typically reserved for a prime, the Canon RF 28-70mm f/2L USM is a wide-angle to portrait-length lens distinguished by its impressively unique f/2 constant maximum aperture. This bright design yields excellent low-light performance along with enhanced control over depth of field for isolating subject matter. Ultra-Low Dispersion glass is employed in the optical design, and greatly reduces color fringing and chromatic aberrations in order to realize high clarity and color accuracy. Complementing the advanced optical properties is Canon's proven ring-type Ultrasonic Motor, which delivers fast and quiet autofocus performance along with full-time manual focus control. Additionally, unique to RF lenses, this 28-70mm incorporates a configurable Control Ring for intuitively adjusting exposure settings, including ISO, aperture, and exposure compensation, from the lens itself.Standard wide-angle to short-telephoto zoom lens is designed for use with full-frame Canon RF-mount mirrorless cameras. Impressively bright f/2 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.Ultra-Low Dispersion (UD) elements are featured in the optical design, and help to suppress color fringing and chromatic aberrations in order to achieve greater clarity and color accuracy throughout the zoom range. A ring-type Ultrasonic Motor (USM), along with an internal focusing design, optimized focusing algorithms, and a high-speed CPU, is employed to deliver fast, precise, and quiet autofocus performance as well as full-time manual focus override. Configurable Control Ring can be used to adjust a variety of exposure settings, including aperture, ISO, and exposure compensation.As a member of the esteemed L-series, this lens has a weather-resistant design that protects against dust and moisture to enable its use in inclement conditions. Rounded nine-blade diaphragm contributes to a pleasing bokeh quality.