> III-2: Lens AF stop button function
> 0: AF stop
> 1: AF start
> 2: AE lock
> 3: AF point: M->Auto / Auto->Ctr
> 4: One Shot AI Servo
> 5: IS start

This is only relivant if you have one of the long white telephoto lenses that have the required "AF Stop" buttons usually situated around the end of the lens. The normal function of this is to over-ride the continuous auto focusing of the camera (in AI-Servo for example) whilst you are tracking some object effectivly locking the focus at the current point (like a temporary manual focus) whilst you hold the button down. The other options 1-5 allow for other possiable actions instead.

> III-7: AF point area expansion
> 0: Disable
> 1: Enable

This is only valid when you have manually selected a single focus point (and are in AI-Servo I beleive). When disabled, it is only that point that is providing focus information to the camera. When enabled, it allows the surrounding assist points that are next to the selected focus point to be used to track possiable focusing targets. (Think of it as making the selected focus point bigger). This is usfull if you are tracking a fast moving object (such as a bird in flight) where you may not be able to keep the selected focus point fully on target.

> IV-1: Shutter button / AF-ON button
> 0: Metering + AF start
> 1: Metering + AF start / AF stop
> 2: Metering start / Meter+AF start
> 3: AE lock / Metering + AF start
> 4: Metering + AF start / disable

This controls what the "half-press shutter button" does as well as what the back "AF-ON" button does when you press it. The / in the above descriptions seporates the two buttons. Allows you to seporate the "Focusing" and "Metering" actions which can be very useful as you can lock focus and exposure independantly before you finaly shoot.

0: Both half-press shutter & AF-ON do the same things, i.e. meter the current view AND start the auto-focus.

1: The half-press shutter still does the same BUT you can temporarily stop the camera from focusing if you HOLD the AF-ON button in. (Useful if you are using AI-Servo and you don't want to change the focus whilst you track, think of this as a temporary Manual focus setting mid shot).

2: Half-shutter ONLY meters it does not focus. Focusing is only done whilst you hold down the back AF-ON button (which also does metering).

3: Half-shutter doesn't focus and FREEZES, i.e. locks in the current metering (that was started by the AF-ON button) ready for the shot. Focusing and metering is started by using the back AF-ON button.

4: Same as 0 but with the AF-ON button doing nothing.

> Should I change something to these parameters for wedding photography?

Experiment first, see which you prefer.