The 2011 EF 400mm f/2.8 that cut 1.5kg — the definitive EF-era sports telephoto.
The 2011 Canon EF 400mm f/2.8L IS II USM cut a remarkable 1.5kg from its predecessor, turning Canon's flagship sports telephoto from a monopod-only tool into a lens that could genuinely be hand-held.
Fluorite elements, a 4-stop stabiliser with panning and erratic-motion modes, weather sealing and Canon's fastest ring USM make it the definitive EF-era 400/2.8.
Its significance is on every touchline of the 2010s: the II is the 400/2.8 most professional sports and wildlife shooters actually owned, and it adapts cleanly to RF bodies.
Used examples are judged on glass and focus: check fluorite elements for cleaning marks, test IS modes for noise, and confirm the focus preset ring works; Mark III carries a big premium so the II is the value buy.