Canon RF 200-800mm F6.3-9 IS USM

Reviewers found it sharp at 200mm and through most of the range, with centre sharpness very good to about 600mm and more average at 800mm, where one tester got better detail by cropping a 600mm shot. Corners are average, which matters less for a lens aimed at central subjects. Colour fringing was easy to see in uncorrected lab files, and there is mild pincushion distortion at 200mm.

Autofocus is quiet and keeps up with subject tracking on current bodies, though near-to-far focus moves are slightly slower than on shorter lenses. Stabilisation allows sharp handheld 800mm shots down to about 1/30 second with static subjects. The f/9 long end is the main limit, pushing ISO up in poor light, and both extenders work but soften the long end further. Testers see it as strong value for the reach.

Owners, mostly bird, wildlife, aviation and sports shooters, praise the reach, sharpness wide open at 800mm and the light weight for the range, and one motorsport shooter now takes it instead of the RF 100-500mm when size is not a concern. One owner using the RF1.4x says it has opened up new subjects, and some give good marks to eye-detection AF on recent bodies.

The complaints are the fixed tripod foot with no click stops, the long zoom-ring throw, f/9 in dull light, heat shimmer at long range, and its bulk in a normal bag. Some report slightly blurred shots at the long end, AF hunting on low-contrast subjects, and slower AF than the RF 100-500mm.