Canon EF 70-200mm f2.8L IS USM

I am in the process of buying the Canon Rebel Xti camera to be used in taking sharp pictures of my kids in sports and other events with low lighting. I am seriously considering purchasing the Canon EF 70-200mm f2.8L IS USM lense. Very high priced but from what I understand, its worth it and very popular.

However, I have read somewhere that this lens isn't intended for a small frame camera such as the Xti. This left me a little confused. Does this mean that this is too much of a lens for the Xti and it wont be able to take full advantage of it? Will I be wasting my money on it?

I have taken great pictures with my EF 70-200mm f2.8L IS USM lens on my old 300D (original Digital Rebel. Used it for my son's soccer and general people photography. The lens absolutely helped take my photography to "next level."

Some lenses are designed for full frame coverage and some for the reduced APS-C sized sensors. This reduces bulk and cost significantly.

Lenses for full frame will more than cover the smaller CCD, but may be relatively heavy and bulky, and, indeed, relatively expensive.

John