Canon's original L-series 500mm f/4 — the first-gen super-telephoto before Mark II improvements.
The Canon EF 500mm f/4L IS USM is the original first-generation Canon 500mm f/4 with IS. It served professional sports and wildlife photographers before the much lighter Mark II and III updated the design.
Optically very good — sharp at f/4 with IS providing approximately 2 stops. Ring USM for fast AF. L-series construction. The f/4 at 500mm provides excellent reach for sports and wildlife with meaningful subject isolation.
Canon EF mount with 52mm drop-in filter holder. Very heavy — approximately 3870g. Full L-series weather sealing. IS. Ring USM. 1.4x and 2x TC compatible. Tripod collar. Professional super-telephoto.
Available used at professional prices. The Mark II (2012) dramatically reduced weight. The Mark III improved further. This original version is the heaviest but cheapest. For budget 500mm f/4 Canon super-telephoto needs.