Canon's L-series superzoom — 10.7x range from 28-300mm with IS, weather sealing, and ring USM AF.
The Canon EF 28-300mm f/3.5-5.6L IS USM was released in 2004 as Canon's all-in-one full-frame L-series zoom, covering a 10.7x range with IS and L-series weather sealing. At 1,670g and 77mm filter thread it is among the heaviest consumer EF lenses. Ring USM provides fast, quiet AF. L-series dust and moisture sealing is built throughout. The 28mm start covers moderate wide-angle and the 300mm end provides super-telephoto reach in a single sealed lens.
The optical design uses 22 elements in 18 groups. Eight aperture blades. The 77mm filter thread is the Canon professional standard. At 1,670g the lens benefits from monopod support for extended sessions. Minimum focus distance of 0.7m throughout. IS provides approximately 3 stops of compensation. Ring USM provides fast, quiet AF with full-time manual override. Variable aperture from f/3.5 at 28mm to f/5.6 at 300mm. L-series dust and moisture sealing.
The 28-300mm L IS USM's L-series sealing differentiates it from the non-L third-party alternatives of similar range: for event, documentary, and outdoor photographers who need the full range in adverse weather, the L-series construction provides reliability that lighter alternatives cannot match. The ring USM AF and IS combination enables confident tracking in situations where lens changes are impractical. The 1,670g weight limits practical carry to single-lens configurations.
On the used market the EF 28-300mm f/3.5-5.6L IS USM is available at L-series telephoto zoom pricing. Condition checks: IS engagement, ring USM AF response, L-series sealing at barrel seams, and 77mm front element for marks. The weight (1,670g) requires consideration for handheld use without monopod support. Compatible with all Canon EOS DSLR and R bodies via EF-RF adapter.