When shooting soccer matches there are a couple of things to consider:
What age are the children? Youngsters (5-10 yrs) play on smaller fields so you can get much closer to the action, and the 70-200 may give you the range (remember that w/10D you have 1.6x focal) effectively 112-320mm.
What time of day? If games are all daytime (mid-day) your lens speed is not as critical (f5.6 can suffice). If you get any late day/twilight game times, then the f2.8 becomes necessary as kids usually do not have field lights like collegiate and pro games do. Also, as the kids get older, the speed of the game increases dramtically, especially the ball speed so lens speed becomes more critical with poor lighting and faster pace of action.
I use the 10D w/70-200 f/2.8L IS USM and when necessary add 1.4x or 2x extender depending on field size and lighting conditions. Takes some thought whereas 100-400mm covers more range without worrying about using an extender. However, you are starting at 160mm if you choose the 100-400mm at the close range so you can't get too close to your near sideline/endline.
I will post a few soccer images from my 12 year olds team in my gallery with and without extender later today. If money is an issue, the 100-400mm is less expensive by a few hundred than the 70-200mm (then add the cost of extenders @ $275 ea.) but I like the quality of the images better when I can shoot without extenders.
Doug
http://www.pbase.com/delta_sierra
Last edited by delta_sierra on Thu Jun 24, 2004 2:09 am, edited 1 time in total.