The Canon RF 600mm f11 IS STM Lens is a super-telephoto, compact and lightweight lens. Featuring a retractable design and a fixed f/11 aperture, this lens's sleek profile makes handheld super-tele shooting a very real possibility, and optical image stabilization further helps to achieve sharp imagery when working in difficult lighting conditions. Also contributing to the reduced size is a distinct optical layout, which uses gapless dual-layer diffractive optics instead of multiple heavier individual elements, which also effectively controls color fringing and chromatic aberrations for high clarity. Complementing this design is an STM stepping motor that delivers quick and quiet autofocus performance that is suitable for both stills and video needs. Additionally, a Control Ring is also integrated into the lens design for intuitive control over exposure settings from the lens itself. If you need more reach, the 600mm is compatible with the 1.4x and 2x RF Extenders for an effective focal length of 840mm or 1200mm, respectively.