Your stuff looks real nice. A bit under exposed for my taste but not technically underexposed, I just like bright shots :P If you don't want to shoot manual and stick to AP or SP, then you could use bracketing. I don't know the layout of Canons, but Bracketing is either setup in your menu or a dedicated button on the body. It let's you shoot multiple shots of the same subject in rapid succession and the camera will automatically adjust to expose the extra shots brighter and darker than the first shot. Giving a range of exposure to later choose from.

I think you're confusing two different subsystems within the camera.

The aperture size governs how much is in focus around your focal point. If your focal point is out of focus then having a small aperture (for the greatest depth of field) doesn't improve things.

The focus system in the Canon's is broken into two sections. The light metering subsystem (full evaluation, partial evaluation, spot and point modes) and the physical sensor that does the focusing. The later one you have little to no control over, the former you can change (well, it really is 3 sections.. the 3rd being the lens you use, but if your lens is the problem it needs to be fixed or replaced =).

The physical focus sensor attempts to separate the item you are focusing from the background. As a result, you run into two issues.

1. You are shooting in overcast or darken area and the lens goes into search mode (does the evil whine as it goes to each of the two focusing extremes).

2. You are zoomed in so close the object that the focus sensor is confused, and can't determine what is foreground and background due to lack of surround background to key off of. This mostly happens when the focus is off extremely, and thus the camera will go into search mode again.

Rarely does "search mode" give you anything useful (and thankfully the 7D lets one turn that feature off), and most of the time it just frustrates the user because for a brief moment you see it go into focus, but the camera doesn't since it isn't checking except at the two extreme ends.

The way to resolve this is during an overcast or darker locations is to change to full evaluation meter mode and maybe focus while zoomed out before zooming fully in. Or bite the bullet and manual focus (what I do half the time with that @#$% micro chainlink fence at Zoos).

BTW the metering mode you are in will change how that EV bar in your view finder will act. On the XSi I shoot anywhere from the -4 to -1/2 EV. I find that if I have Full-evaluation on during bright sunny day I go further negative.

However, the EV meter is rarely right on the XSi. The best advice I can give you is when you are shooting in slightly different lighted scene you back your eye away enough to glance down to see if you are getting a good contrast between light and dark. Also, turning on your RGB + Flashy will help as well since you're not looking for composition (you should have done that in the view finder), but you are looking to ensuring the exposure is right.

I was happy when I moved from the XT to XSi since it allowed me to do full manual mode. But it also requires thinking a bit more about what each setting does, and how you want to make use of it.

What you posted were nice. Wet pavement is always a killer if your focus point is mistakenly on it since the camera will never completely focus right.

o.o

Admittedly, I never really understood the difference between metering modes, but focusing and aperture size were never really an issue. XD I appreciate the advice, though - I'll be sure to do a little studying and experiment with different metering modes.

Aperture priority has always been the preferred m.o. of sports and action photographers. There's absolutely no reason to fear it will make you lazy or unable to use your camera's potential fully.

Keep using it and learn to use AE lock and AE compensation.