Canon's first-generation stabilised 70-200mm f/2.8L, adding IS to the professional telephoto.
The Canon EF 70-200mm f/2.8L IS USM was released in 2001 as the first image-stabilised version of Canon's professional constant f/2.8 telephoto zoom, establishing a lens category that subsequently defined professional event, wedding, and sports photography on Canon DSLR bodies. The L-series build quality and weather sealing are built throughout the ring USM design. It was replaced by the IS II in 2010 with a more modern IS mechanism and a lighter optical formula; the original IS remains available on the used market at significantly reduced prices.
The optical design uses 23 elements in 18 groups. Eight circular aperture blades produce smooth bokeh. The 77mm filter thread is the Canon L-series telephoto standard. At 1,590g the lens is the heaviest of the three IS versions (IS I/II/III), reflecting the original optical and IS mechanism design. Minimum focus distance of 1.4m. IS provides approximately 2 stops of compensation — less than the IS II and IS III. Ring USM provides fast, quiet AF with full-time manual focus override. Constant f/2.8 aperture throughout.
The IS I's image quality is L-series standard and optically competitive with the IS II and IS III for stills at most apertures — the practical differences are the older IS mechanism (approximately 2 stops vs IS II's 4 stops), the heavier body, and the 2001-era weather sealing. For photographers who need the 70-200mm f/2.8L range and IS for less demanding handheld stills work, the IS I provides the full constant f/2.8 capability at a fraction of IS III prices. The ring USM AF is fast and reliable.
On the used market the EF 70-200mm f/2.8L IS USM (original) is very affordable compared to IS II and IS III. Condition checks: ring USM AF response, IS engagement, weather sealing at zoom barrel and tripod collar ring, and front element for coating marks. The heavier build means a used example may show more wear than a lighter lens at the same shutter count. The EF 70-200mm f/2.8L IS II USM provides more modern IS and a lighter formula at a modest premium on the used market. Compatible with all Canon EOS DSLR and R bodies via EF-RF adapter.