The Canon RF 100-400mm f/5.6-8 IS USM is a telephoto zoom lens designed for Canon's RF mirrorless mount, aimed at wildlife, sports and aviation shooters who need long reach in a compact, lightweight package. Its variable f/5.6-8 maximum aperture keeps the optic small and affordable relative to professional super-telephotos, while the built-in IS and USM autofocus motor make it well suited to handheld use on EOS R-series bodies.

Sales data is extremely thin: a single UK auction hammer result of £350 from October 2023 is the only datapoint available, so a meaningful price range or median cannot yet be established. As of today in 2026 that figure suggests the lens sells for noticeably less at saleroom level than current retail, but with only one verified result the wider value picture remains uncertain and buyers should treat it as indicative rather than definitive. Hammer prices exclude buyer's and seller's commission, so the true cost to a winning bidder is higher than the headline figure.