Canon EF 400mm f/2.8L IS USM

Manufacturer's Description:

"The EF 400mm f/2.8 L IS USM is a new generation super telephoto 400mm lens with a large aperture ratio of f/2.8 and first rate imaging performance. With image stabilization effective over two shutter speeds this lens stands out.

You can have reliable capabilities when used for fashion photography performed indoors and at night. The optical system includes one fluorite and two UD lenses that eliminate secondary spectrum, for ultra high contrast and image quality.

Its fast too
With ring USM drive, inner focusing and an improved drive algorithm, its autofocusing is the fastest in the world (when used with the EOS-3).

Closest focusing distance has been reduced to 3m/ 9.8 ft., it is also equipped with a full time manual focus mechanism that does not consume electric power. It offers both focus preset and AF Stop functions.

This lens is 700g/ 1.5 lb. lighter than its predecessor due to the use of a magnesium alloy for its barrel and other external parts. It offers superior dust-proof and moisture-proof performance even under harsh conditions."