Canon 10d focus - need words of wisdom

[nu2canon]

Hi, I just found this forum last night and I'm impressed by the amount of help and information shared here. This is a great resource.
I just recieved my new 10d along with a couple of beautiful L lenses. (I'm a former Nikon film SLR owner, older slower focusing cameras.) I'm new to the the Canon system and have a couple of questions regarding using the multiple focus points in the viewfinder.
So far I've had the best results using just the center focus point, and setting the focus to 'one shot'. I'm confused though. At what point is it beneficial to switch from using just the one focal point to using all of them, or to switching to a different focus mode than the 'one shot'?
My subjects are mainly people. I'm finding that by using the center focus I can focus on the eyes and then recompose. I'm getting good focus on 'stationary' subjects, but not so good on moving targets (kids).
I've set the ISO to 800 and using AV mode with an aperture of 5.6-8 for kids shots.
I need to spend a LOT of time practicing, but I'd love to hear some advice on what works best from you experienced people. I'm so used to the older slower focusing cameras, but I'd love to be able to utilize all of the newer features of this camera.
Thanks
Nancy

[KennyG]

I'll try and keep this short.

You will use single centre point the most.

Multiple points are useful if you have one subject moving in the frame (bird against the sky for example), otherwise it will simply grab the point that is over something with the highest contrast.

One point other than centre can be useful if, for example, you are taking a portait in portrait orientation, then use the point closest to the eyes.

Single shot is what it says. Point at a stationary subject and shoot.

AI servo will track a moving subject and adjust focus on the fly. This is most suitable for things like field sports or motor racing.

I know it is a lot more complicated than that, but I hope this helps.

[dtsang831]

This link might give you some more details regarding your 10D's focusing functions and more....

http://www.shortcourses.com/10D/focus.htm

Enjoy your new camera.

[robertwgross]

AI servo will track a moving subject and adjust focus on the fly. This is most suitable for things like field sports or motor racing.


A question, KennyG:

Does that work best when you are panning the camera and the subject, like an auto, is moving within the frame, but maybe you are panning to keep the auto centered?

---Or---

Does that work best when you are not panning, and the subject is moving around within the frame?

In my mind, I visualize a bunch of curves heading toward a straightaway, and the photographer is situated at the end of the curves. The auto is heading in the curving path toward the camera. So, the autofocus has to be "pulling in" as the auto is approaching. Then it might have to be fighting for a focus point if the auto is weaving around within the frame.

What works best?

I guess that's why they call it AUTO-FOCUS.

---Bob Gross---

[nu2canon]

Thanks for the information and the link.