Canon RF 800mm F11 IS STM

Reviewers find the centre very good to excellent, with borders a step behind and the f/11 aperture setting a ceiling on fine detail through diffraction. Lateral colour fringing is low and almost invisible after correction, distortion is negligible, and corner shading at f/11 is moderate. Background blur is smooth, with slight outlining in highlights and cat's-eye shapes towards the edges. Expect high ISO settings much of the time, and adding an extender at f/16 or f/22 limits image quality further.

Autofocus is quiet and accurate most of the time, with speed described as anywhere from decent to quick, and the AF area is restricted to the central part of the frame. The 4-stop IS works well but feels modest at 800mm. Handling criticisms are consistent: no weather sealing, a 6m minimum focus distance, a fixed tripod foot that cannot rotate to portrait, and an optional hood. Even so, testers see it as remarkable value that makes 800mm practical for amateurs.

Owners, mostly bird photographers, praise the reach per dollar and how light it is, saying they can hand-hold it for an hour or more and pack it into a normal camera bag. Sharpness is described as good, if a little behind the RF 100-500mm, and hand-held moon shots surprise people.

The complaints are the f/11 aperture in shade and poor light, the 6m minimum focus when shooting from a hide, the small AF area on the EOS R5, the difficulty of finding birds in flight in such a narrow view and the lack of an included hood in wet weather; one owner advises against using a teleconverter with it.