Next lens for outdoor sports

I am fairly new to DLSR photography so I want to make sure there is something I'm not missing here before I pull the trigger on my next lens purchase.

I have the XT with the Kit lens and the 85mm f1.8 so I could shoot my daughters gymnastics meets. Good lens for that purpose.

Since then, I am thinking about some more reach and have been wavering between the 200mm f/2.8 prime and the 70-200mm f/4 (non-IS). I think I'm settling upon the 70-200.

Here are the intended uses of my next lens:

90% of the time:
This spring both daughters will be doing outdoor High School track and field. Then in the fall they will be doing cross country. The foot zoom works for Track as I can see and move to and from the action at will, So I'm sure the 20mm prime will work fine for that (or perhaps even my 85mm). However for Cross country, I usually only see them a couple of times during the meet and this is where a zoom may come in handy over the prime. I could get shots as they approach and then again as they pass by with the zoom. Whereas, with the prime I may miss a few opportunities.

The remaining 10% of the use would be for a general purpose lens....summer vacations, trip to the zoo etc. I think the zoom would be more useful for these uses.

I think for the above uses, the zoom makes more sense than the 200mm prime. I know I'll miss out on the extra stop if I go with the 70-200, but I figure if I really need it, I can always put the 85mm f/1.8 on the camera and use the foot zoom on an overcast day or late in the day. I think most days the f/4 will be good enough. Also, I've ruled out the IS version of the 70-200 since I can't justify the extra $400-$500 if I'll be using this 90% of the time to freeze action (i.e. SS's over 400). I don't expect to see much of a difference in IQ or AF between the two L lenses.

So, please check my logic on this as I'm not that confident in my decision making ability given my limited experience. Also, if there is something else I should be considering in this price range, I'd appreciate the comments.

Thanks
Mike

Start with the zoom. Then you will gain some experience on just what focal length(s) you need for later purchases. EF 70-200/4 is a good one. IS version if you can afford it.

I would say a 400mm 2.8L IS.... lol jp. Go with the 70-200 f/4

Sigma 100-300 f/4 is a great lens for that purpose

for a cheap option, get the sigma 70-200 f2.8 DG APO HSM EX (non-macro) - u can get these used from keh.com for similiar price to the 70-200 f/4 non-IS but gain that extra f-stop

crazyskillz07 wrote in post #5209368
I would say a 400mm 2.8L IS.... lol jp.

I already have 1 in college and these 2 will be there shortly. While that would be a dream lens, it would likely add another year of tuition

Unless it is really cloudy and gloomy, f4 is usually enough to shoot outdoors. Get the zoom. If you find yourself looking for more reach and don't want to spend to much extra money you have two options...
A - 70-200 + 1.4x extender
B - 70-300IS

JCheungPhoto wrote in post #5209376
for a cheap option, get the sigma 70-200 f2.8 DG APO HSM EX (non-macro) - u can get these used from keh.com for similiar price to the 70-200 f/4 non-IS but gain that extra f-stop

I heard it's a good lens but big and heavy - like the canon 70-200 f/2.8(about double the weight of the 70-200 f/4).

Yet another trade off to consider. 2.8 comes at the cost of weight/size. I'm not getting any younger and that may mean using a monopod more than I'd like. Hmmmmm.

not that heavy compared to what you gain (300mm and 420mm with a 1.4x tc)

I struggled with that same decision two years ago and ended up with the 70-200mm f/4L. I never regretted it. I must say, though, that I was never 100% satisfied with the lens either. It was frustrating to have to keep the shutter speed above 1/250. The IS version opened a lot of creative windows since I can now shoot down to about 1/13 sec.

Rubberhead wrote in post #5210444
I struggled with that same decision two years ago and ended up with the 70-200mm f/4L. I never regretted it. I must say, though, that I was never 100% satisfied with the lens either. It was frustrating to have to keep the shutter speed above 1/250. The IS version opened a lot of creative windows since I can now shoot down to about 1/13 sec.

True....but for shooting track and field, I think I'll need those SS's or faster anyways to freeze the action.

I would love to get the IS version, but not sure I can justify the cost.