Canon RF 100-300mm F2.8 L IS USM

Testers put its image quality on a par with top prime lenses. It is very sharp from the centre to the extreme corners at f/2.8 throughout the zoom range, and chromatic aberration is close to invisible apart from a little fringing at the frame edges at the short end. Distortion is slight, and the light vignetting at 100mm f/2.8 is gone by f/5.6. Bokeh is smooth and ghosting and flare are well controlled.

Autofocus is very fast, accurate and almost silent, with a high hit rate on moving subjects, and the stabiliser lives up to its 5.5-stop rating. Image quality holds up well with both RF extenders in real-world use. The drawbacks are the price, the 2.6kg weight for long handheld sessions, the rare and costly 112mm filters, a noisy zoom mechanism, front focus buttons that are awkward to reach, and a tripod ring that stays on the lens with a foot that is not Arca-type.

Wildlife owners value the f/2.8 aperture at dawn and dusk and the ability to zoom out when animals come close, which a long prime cannot do. One owner who also uses a 600mm f/4 says this lens took the place of a 70-200mm f/2.8, a 100-500mm and a 400mm f/2.8 in his kit, and that it still performs superbly as a 140-420mm f/4 with the 1.4x extender.

Another owner made it his main safari lens for a couple of years, sometimes with the 1.4x, but later left it at home in favour of a lighter, slower 100-400mm zoom for its flexibility and weight. Cost and weight are the trade-offs these owners mention.