Good canon lens for outdoor sports? Rebel t1i?

Alright, this year I'm going to have to take a lot more sports photos for my yearbook. This past year our previous photo editor took most of the outdoor sports and I helped with indoor like basketball since i have an 85mm f/1.8. He graduated and now I'm going to be responsible for a lot of the outdoor sports photos as well and therefore I need a new lens to do so.

My yearbook adviser is a photographer too and buys gear, but it's all nikon --- I can use his cameras and lenses, but it's annoying to keep switching back and forth. ANYWAY, I was looking at the 70-200mm f/4L USM or the 70-300mm f/4-5.6 IS USM. It's going to be a birthday present and I don't want to ask for anything TOO expensive… But if a lot of money must be spent then so be it.

So would either of these lenses be ok? Which should I pick over the other? And Any other suggestions/recommendations?

Oh and if you're thinking "For a high school yearbook?" (it's actually a pretty big thing lol) I also enjoy photography as a hobby, and for better results I'm going to need new gear now and then.

I'd think seriously about the 55-250mm, it's about the same price as the 70-300, but a far better lens.

The L-series are superb, but don't come cheap.

Of the two you mentioned the 70-200 is the better lens but you do lose some reach. The 70-300 will give you the reach but you will definetly lose on low light ability.

Now the problem you are going to have is that neither are very good in low light though the 70-200 is better. It won't be a problem in daylight games but for those night time football games it can be. Even with the ISO jacked up to 1600 you will have a tough time getting a fast enough shutter speed to freeze action even with the 70-200. The 70-300 will be nearly useless at night.

Ideally what you would want would be the 70-200mm F2.8L and or a 300mm F2.8 but these are very expensive. If you don't mind zooming with your feet a 200mm F2.8 maybe a good choice.

Andrew is confusing his Canon seventy something to 300mm lenses. He is thinking 75-300. Which indeed cots the same as a 55-250 but has no IS.

The 70-300 with IS is a decent lens but the 70-200 L with IS is even better.

If you are unsure of which lens is for you then the $700-1000 you are proposing spend is a lot of cash to get wrong! Why not rent a couple of lenses for a day so you can choose the right one for you.