I need a little advice here. Whenever I try to take pictures of people moving (kids playing for example), I put my T1i into servo mode. As soon as the camera goes in servo, the shots tend to be OOF. If I shoot something a little more still in One Shot, the photos come out great.
Is there a greater chance of getting these OOF shots if I use a wide aperture?
Here is an example: I shot at f/2.8 and 1/200.
If I'm doing this wrong, what settings should I have used? Also when do you switch from One Shot to Servo mode?

Do you think the f/2.8 has anything to do with it? Or once I start tracking correctly, they should come out fine?

