A few camera questions

A few questions for you all:

I don't know if other camera models have this, but on the XTI there are 3 AF options, "One Shot" (focuses and keeps it that way), "AI Focus" (Decides weither or not to use One shot or our next choice) and "AI Servo" (Auto focuses to the subject whenever it moves without having to refocus the picture)

Is there any disadvantage to using AI Servo, because if there isn't, it sounds like a great feature to use while spotting!


another question:

What metering mode is the best? (Evaluative, partial, or center-weighted average)?

Thanks ahead of time,

-Matt

My camera has something similar. I suppose AI Servo would use up your battery faster.

I've been playing around with the metering option too. For a moving target, such as a jet landing overhead, I've found center-weighted average works best, probably because there are just so many surfaces on an airplane, and they all reflect light at different angles to the camera.

I use AI Focus, I like to ensure the camera gets a focus lock right before I shoot. As for metering mode I'm not sure if the Xti is like the 30D but I clear that feild all together.