Sigma 200-500mm f/2.8 EX DG US$25,999
Each year at the U.S. Imaging EXPO, Sigma would place a gigantic military-green lens at its booth. The lens is a 200-500mm f/2.8, the world's only zoom length to reach 500mm and have a constant f/2.8 aperture.
The lens is undoubtedly most suitable for wildlife and sports imaging and would even befit astronomical photography. Lithium batteries in the lens power its zoom and auto-focus. An LCD screen on the barrel shows the data such as focal length and object distance.
The lens has different bayonet sockets to make it compatible to various name brand cameras, primarily the Canon and Nikon series.