RF-Mount Lens/Full-Frame Format Fixed f/11 Aperture Retractable, Locking Lens Barrel Gapless Dual-Layer Diffractive Optics Super long reach, super compact design, the Canon RF 800mm f/11 IS STM is a unique telephoto prime featuring a distinct mixture of focal length and form factor. Characterized by its retractable design and a fixed f/11 aperture, this lens's sleek profile makes handheld super-tele shooting a very real possibility
