which focusing setting should I put my 30d on??

[MichelleK]

Now that I have the option of changing the AF should I have it at

one shot
AI focus
AI Servo

I shoot mostly my one and two year old....sometimes they are still sometimes they are moving, sometimes they are still until I press the shutter button then they are moving.

Michelle K

[Jon]

If your subject's going to hold still, One Shot's best. If your subject is moving, AI Servo will track it as it goes. AI Focus is designed to shift gears as necessary, so gives you the worst of both (it may lag a bit before shifting gears into Servo mode). I'd be inclined to go with AI Servo, since they're more likely to be moving or about to move.

[Curtis N]

Custom Function 4-1 (using the * button to focus) and AI Servo. Hold the button down for moving subjects, or push it to focus and release for stationary subjects.

I agree with Jon about AI Focus mode. It's nearly useless.

[Mitcon]

I second what Jon has said, AI servo would be the way to go.

[Digitalwave]

I second what Jon has said, AI servo would be the way to go.

AI Servo is really annoying to try and use for stationary photos though. It's easy enough to alternate between One Shot and AI Servo when needed though, that is what I do.

[Rumjungle]

AI Servo all the way. Capturing moving subjects (especially the little ones:) ) pretty much demands it. As Curtis said, use the * button for AF.

[delhi]

why not just leave it as AI Focus.

[Curtis N]

why not just leave it as AI Focus.My experience with that mode has been that the camera won't kick into Servo until the subject is REALLY out of focus. After struggling with it on the 300D for several months, I finally bought a 20D so I could tell the camera what to do, not the other way around.AI Servo is really annoying to try and use for stationary photos though.The only time I don't use Custom function 4-1 is when I'm using a remote shutter button. In those cases I focus with the remote and the beep it gives to confirm focus in one-shot mode is nice. I can keep my hands and face away from the camera.

[mrklaw]

if you use cf 4-1, and press once (simulating one shot focus), does it do a full focus, or does it only focus for as long as you are holding it down?

[loon]

depends on how much light is available and how fast your autofocus is. usually instant if conditions are good. i just keep it pressed until you get focus confirmation light