The Canon 800mm f/11 IS STM is an impressively compact and lightweight prime lens, considering the incredibly ultra-telephoto field of view it provides. Designed for full-frame Canon RF-mount mirrorless digital cameras, this lens features a retractable/extendable design and a fixed f/11 aperture, which contributes to its sleek and portable form factor and balanced mixture of depth of field and sharpness. With handheld super-telephoto shooting a real possibility with this sleek lens, the optical image stabilisation benefits by minimising the appearance of camera shake by up to four stops. Further contributing to the reduced size of the lens is the utlisation of gapless dual-layer diffractive optics, which also aids in achieving sharper and clearer imagery by minimising chromatic and spherical aberrations. A STM stepping motor complements the optics with deliverance of fast and quiet autofocus performance that suits both stills and video applications. For an intuitive tactile control, a configurable Control Ring permits adjustment to exposure settings --aperture, ISO, and exposure compensation-- from the lens itself. This lens is compatible with the separately available RF 1.4x Extender and the RF 2x Extender if extension of the effective focal length to 1120mm or 1600mm, respectively, is desired.