Canon has also today announced two new lenses. The EF 16 - 35 mm F2.8L USM is a new wider version of the 17 - 35 mm, matched up to the new EOS-1D SLR it can provide a field of view equivelant to a 21 mm lens on a 35 mm film camera. The 400 mm F4 DO IS USM is a lens we first saw at Photokina last year. It features a unique multi-layer diffractive optical element which has allowed the designers to make the new 400 mm DO 1 KG lighter and 84 mm (3.3 in) shorter than the old 400 mm F4.