Opinions for a newbie please.

I have only been shooting for a couple of years, and my passion is race cars. I use a digital Rebel, and am looking into zoom lenses. I already know I cannot afford the 70-200 f2.8 IS lens, so Im checking either the 70-200 f4 IS or the f2.8 non IS unit. Could I get some advice on which one would better suit photos of cars going by (panning) as well as still drag race launch shots? Thank you very much.

If you shoot the race cars from a tripod, IS is not necessary and I would choose for the extra stop (i.e. F/2.8 ). If you plan on shooting handheld as well, I would prefer the F/4 IS because of the IS and the lower weight.

The tripod is the best/fastest way to "speed up" a lens.

OP is talking about panning of moving race cars. If it's in the daylight I would think the 70-200mm F4L would be suitable. If you are doing alot of dusk/night shooting definitely get the 2.8. IS does nothing for moving objects.

Curiously enough,a tripod will pan.

Cough...cough.

Relentless Pursuit wrote in post #10260919
Curiously enough,a tripod will pan.

Cough...cough.

It sure will, but when panning I like to be more mobile. I think a monopod works better for me than a tripod. But to each his own.