Canon RF 800mm f/11 IS STM Review

The Canon RF 800mm f/11 IS STM is a unique ultra-telephoto lens that makes extreme reach accessible to Canon mirrorless shooters on a budget. At just 1260 grams and collapsing down to 28cm with a retractable barrel, it's remarkably portable for an 800mm optic. The fixed f/11 aperture is the trade-off for this compact design, which means you'll need good light or higher ISOs, and the lack of aperture blades eliminates traditional bokeh control. Four stops of image stabilization help with handheld shooting, and the STM motor provides reasonably quiet autofocus for stills and video.

Reviewers find the lens delivers surprisingly sharp images in the center when stopped down or used at native aperture, especially given the price point. The diffractive optics keep chromatic aberration well controlled. However, the fixed f/11 limits low-light performance and forces reliance on modern high-ISO bodies, and autofocus can struggle in dim conditions or with fast-moving subjects. Edge sharpness isn't spectacular, and the slow aperture restricts creative background separation. For wildlife and birding photographers who prioritize reach and portability over speed, it's a capable tool that punches above its weight class.