The revolutionary Canon EF 400mm f/4 DO IS USM was launched in 2001 and was a compact telephoto prime lens that was way ahead of its time – and was the shape of smaller lens technology to come with Canon’s RF range of smaller, more compact telephoto zooms we see today.
It’s been 25 years since the Canon EF 400mm f/4 DO IS USM stunned and intrigued the photographic community, as the world’s first super telephoto lens incorporating the exclusive Canon-developed multi-layer Diffractive Optics (hence DO in lens title).
