Canon RF 600mm F11 IS STM

Reviewers found image quality good for the price: sharpness is fairly even across the frame, chromatic aberration is almost absent and distortion is negligible even with corrections off, though one lab expected more centre resolution from a fixed-aperture prime. There is some corner light falloff at f/11, and the bladeless aperture gives round out-of-focus highlights.

Autofocus was quick, quiet and accurate in good light, including subject tracking on an EOS R5, and the 5-stop stabiliser allowed sharp hand-held shots at 1/30 sec. Ghosting and flare resistance is decent with the hood. The criticisms are the fixed f/11, which limits it to bright light or high ISO, no weather sealing, a fixed tripod socket that cannot rotate to portrait, some doubt about the long-term durability of the retracting barrel, and a hood (ET-88B) sold separately.

Owners like the low price, light weight and reach, saying it is light enough to carry for hours and works very well in good light. Several found it very sharp for the cost, even when cropping heavily, and praise the image stabiliser.

The f/11 aperture is the most common drawback in low light, and some mention a learning curve and a too-brief manual. Others found autofocus slow and sharpness disappointing, and one notes the lens is not weather sealed.