Lens for Airshows/Model Aircraft

Hi,

For Christmas my wife got me a Rebel Xti. My ultimate passion is aviation, full scale and radio controlled.

I had thought that the Canon 70-300mm IS would be a good lens for shooting in-flight images. But after reading some of the threads here, I'm confused....again. The IS doesn't appear to have an advantage in this area.

I don't want to spend over 700 dollars on the lens and I'm really new at this SLR stuff.

Can you help me pick a decent affordable lens for my planned task?

Thanks

I don't know, I think you ought to try the 70-300 IS before abandoning it. I've not tried one with fast-moving objects yet, but I would think that it could do well at an air show.

I know that it doesn't have the fastest focus mechanism in the world, but I would think that once your target is 30 or 40 feet away, the necessary movement of the mechanism is pretty small.