A 70 - 200 zoom lens is a must have lens for all photographers. If you shoot a Canon dslr camera you won't go far wrong with the 70 - 200 f2.8L IS USM lens. This is a very popular lens amongst professional photographers and when you see what this lens is capable of it is easy to see why.
dslr lenses- get to know all about telephoto, prime lenses, wide angle and kit lenses! Which to use for faces, which to use for places, and everything in between. (great info for beginner photographers)