Canon RF 100-500mm f/4.5-7.1 L IS USM

Pros

• Exceptional sharpness and image clarity across the zoom range
• Fast and reliable autofocus that performs well even on crop-sensor bodies like the R7
• Lightweight and compact enough for handheld use and long hikes
• Superior build quality and weather sealing typical of the 'L' series
• Excellent image rendition, color, and contrast

Cons

• Slow maximum aperture (f/7.1) at the 500mm end can limit performance in low light
• High price point, with some users questioning if it is worth the significant premium over the RF 100-400mm
• Ergonomic issues with the focus ring being placed too close to the camera body, making it difficult to balance when manual focusing
• Physical design prevents the lens from being fully retracted when a teleconverter is attached

Caveats

• The lens is noticeably darker than some EF-mount predecessors, though it maintains f/5.6 and f/6.3 through much of its range
• Some users feel the modern 'plastic' exterior feels less robust than older EF L-series lenses, despite the high cost
• Teleconverter usage is restricted to the 300-500mm range of the zoom

Best for

• Wildlife and bird photography
• Outdoor sports in decent lighting
• Travel and hiking where weight is a primary concern
• Canon R-series users looking for a significant upgrade from the non-L telephotos

Avoid if

• You primarily shoot indoor or night sports where a faster aperture is required
• You are on a strict budget and can achieve 'good enough' results with the RF 100-400mm
• You require a lens that can fully retract while a teleconverter is mounted